GEOSCAN, résultats de la recherche


TitreTGI 4 - intrusion related mineralisation project: new vectors to buried porphyry-style mineralisation
AuteurRogers, N; McClenaghan, B; Plouffe, A; Kellett, D; Chapman, J; Azadbakht, Z; Tweedale, F; Ruberti, G; Anderson, B
SourceNew Brunswick Exploration, Mining and Petroleum conference program and abstracts volume; 2014 p. 88
LiensOnline - En ligne
Séries alt.Secteur des sciences de la Terre, Contribution externe 20130536
Éditeurtment of Mines and Energy New Brunswick
RéunionNew Brunswick Exploration, Mining and Petroleum Conference 2014; Fredericton; CA; Novembre 2-4, 2014
Mediaen ligne; numérique
Sujetsminéralisation; porphyres; gisements porphyriques; altération; géologie économique
ProgrammeInitiative géoscientifique ciblée (IGC-4)
Résumé(disponible en anglais seulement)
Intrusion related (e.g., porphyry) mineralisation is the world's most important source for Cu, Mo, W and Sn. Porphyry deposits are typically large, low- to medium-grade deposits where the mineralisation is hosted within and immediately surrounding particular intrusive phases within a larger intrusive complex. In order 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 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 within the root systems of fertile intrusive phases that conditions were met that triggered a hydrothermal-magmatic system of size and duration sufficient to develop a large porphyry deposit? To help answer these questions studies have been undertaken on the Triassic- Jurassic porphyry deposits of the BC interior and the array of mineralised Appalachian Siluro-Devonian intrusions, such as those of central New Brunswick. The alteration halos and vein systems associated with intrusion related mineralisation have the potential to represent much larger exploration targets than an actual economic orebody itself. Determining the characteristics in these distal features that distinguish mineralised from barren systems can form the basis of an exploration strategy for otherwise hidden deposits. A common problem facing Cordilleran and Appalachian exploration is how to detect mineralised sequences through the extensive surficial coverage. Consequently research activities are focussing on till geochemical and indicator mineral dispersal patterns of intrusion related deposits. Structural relationships indicate that Sn-W-Mo mineralised intrusive systems can form due to extension associated with far removed accretion. Deposits within these bodies form along fluid pathways, such as the intersection of highangle 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 physio-chemical variations that relate to magma fertility.