GEOSCAN, résultats de la recherche


TitreIdentifying new vectors to hidden porphyry-style mineralisation
TéléchargerTéléchargement (publication entière)
AuteurRogers, N; Plouffe, A; Chapman, J B; McClenaghan, M B; Kellett, D A; Anderson, R A
SourceTGI 4 - Intrusion Related Mineralisation Project: new vectors to buried porphyry-style mineralisation; par Rogers, N (éd.); Commission géologique du Canada, Dossier public 7843, 2015 p. 249-291, (Accès ouvert)
LiensCanadian Database of Geochemical Surveys, downloadable files
LiensBanque de données de levés géochimiques du Canada, fichiers téléchargeables
ÉditeurRessources naturelles Canada
Documentdossier public
Mediaen ligne; numérique
Référence reliéeCette publication est contenue dans Rogers, N; (2015). TGI 4 - Intrusion Related Mineralisation Project: new vectors to buried porphyry-style mineralisation, Commission géologique du Canada, Dossier public 7843
ProvinceColombie-Britannique; Nouveau-Brunswick; Terre-Neuve-et-Labrador; Nouvelle-Écosse; Ontario
SNRC92I; 92P; 93A; 93B; 21A; 21G; 21H; 1M; 11D; 11E; 11P/13; 11P/14; 11P/15; 11P/16; 32D/01; 32D/02; 32D/07; 32D/08; 21G/14; 21G/15
Lat/Long OENS -68.0000 -61.5000 46.0000 45.0000
Lat/Long OENS -56.5000 -55.0000 48.0000 47.5000
Lat/Long OENS-124.0000 -120.0000 53.0000 50.0000
Lat/Long OENS -78.4000 -78.4000 48.2833 48.2167
Sujetsgisements porphyriques; cuivre porphyrique; prospection minière; dépôts glaciaires; tills; analyses de till; géochimie du till; exploration de dépôts glaciaires; dépôts glaciaires; végétation; écoulement glaciaire; directions des mouvements de la glace; levés biochimiques; biogéochimie; profils de dispersion; minéralisation; altération; éléments d'indice; tungstène; molybdène; étain; bismuth; échantillons globaux; gisements minéraux; interpretations structurelles; modèles tectoniques; milieux tectoniques; éléments tectoniques; molybdenite; roches intrusives; roches granitiques; inclusions fluides; quartz; métallogénie; analyses pétrographiques; granodiorites; pétrogenèse; cuivre; or; gîtes magmatiques; altération hydrothermale; filons de quartz; gisements filoniens; gîtes granophyriques; datations au uranium-plomb; datations radiométriques; roches ignées; Archéen; gisements minéraux hydrothermaux; antimoine; magmatisme; Mine Gibraltar ; Dépôt de Mount Pleasant ; Granite de Belleoram ; Batholite de South Mountain ; Groupe de Broad River ; Orogenèse Acadienne; géologie économique; géologie des dépôts meubles/géomorphologie; minéraux métalliques; Dévonien; Précambrien; Paléozoïque
Illustrationslocation maps; photographs; cross-sections; photomicrographs
Bibliothèque de Ressources naturelles Canada - Ottawa (Sciences de la Terre)
ProgrammeÉtude des gîtes porphyriques, Initiative géoscientifique ciblée (IGC-4)
Diffusé2015 06 11
Résumé(disponible en anglais seulement)
Intrusion related (e.g., porphyry) deposits are the most important sources for Cu, Mo, W and Sn, along with Au, Ag, and PGEs. Porphyry deposits are large, low- to medium-grade deposits in which mineralisation is hosted within and immediately surrounding distinctive intrusive phases within larger intrusive complexes that commonly have prolonged emplacement histories. To develop more effective exploration criteria to identify and evaluate deeply buried and/or hidden fertile intrusive mineralizing systems, studies into Cu-Mo/Au and W-Mo-Sn systems are aimed at answering the following questions: i) Are there distinctive proximal and distal footprints for each deposit type that will allow identification of, and vectoring towards hidden economic deposits?; ii) Is there evidence of fertility within the root system of intrusions, i.e. what are the triggering conditions and indicators of an hydrothermal-magmatic system of size and duration sufficient to develop a large porphyry deposit? To help answer these questions studies are being undertaken at sites associated with the Triassic-Jurassic porphyry deposits of the British Columbia interior and for the array of mineralised Canadian Appalachian Siluro-Devonian intrusions, for which the fundamental geoscience knowledge is often lacking.
A common problem facing Cordilleran and Appalachian exploration is how to detect intrusion-related mineralization through the extensive glacial sediment cover. Consequently, research activities are focussing at identifying key geochemical and mineral indicators in till near known mineralization and their detrital dispersal down-ice. Indicators are being developed for the detection of mineralization, but also the alteration halos and vein systems associated with mineralization, which represent much larger exploration targets than the actual economic orebody itself. Once identified in till, these indicators can be traced to their bedrock source using reconstructed ice movement vectors.
Structural relationships indicate that Sn-W-Mo mineralised intrusive systems can form due to extension associated with far removed non-orthogonal accretion. Deposits within these bodies form along fluid pathways such as the intersection of high-angle syntectonic breaks. Mineral potential can also be resolved through trace element fingerprinting. Subtle compositional changes in commonly occurring minerals (i.e., biotite) and fluid inclusions provide evidence of chemical variations related to magma fertility and vectors to mineralisation.