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TitreMuon Geotomography - Bringing new physics to orebody imaging
AuteurBryman, D; Bueno, J; Davis, K; Kaminski, V; Liu, Z; Oldenburg, D; Pilkington, M; Sawyer, R
SourceSociety of Economic Geologists, Special Publication 18, 2014 p. 235-241
Année2014
Séries alt.Secteur des sciences de la Terre, Contribution externe 20140100
ÉditeurSociety of Economic Geologists
Documentpublication en série
Lang.anglais
Mediapapier
Formatspdf
ProvinceColombie-Britannique
SNRC92F/12; 92F/13
Lat/Long OENS-124.0000 -123.5000 50.0000 49.5000
Sujetsinterprétations géophysiques; levés géophysiques; géophysique
Illustrationsphotographs; plots; cross-sections
ProgrammeDeveloppements methodologie, Initiative géoscientifique ciblée (IGC-4)
Résumé(disponible en anglais seulement)
Muon geotomography, a novel geophysical exploration and imaging technology, uses cosmic rays to create three-dimensional (3-D) images of subsurface density distributions. The first controlled field test confirming the capability of muon geotomography for imaging a dense orebody in a complex geologic environment was conducted at the Price volcanic-hosted massive sulfide (VHMS) deposit, Vancouver Island, British Columbia, Canada. The semimassive and massive polymetallic mineralization of the Price deposit is situated in a Paleozoic stratigraphic package of rocks known as the Sicker Group including the Price, Myra, Thelwood, and Flower Ridge Formations, indicative of volcanic rocks formed in a rifted oceanic island-arc system. The field application involved placing a sensor with an active area of 1 m2 beneath the massive sulfide orebody in an underground tunnel for exposures of about two weeks at several locations. Muon flux data were inverted to recover a 3-D density image of the deposit. The inverted data were in good agreement with drill core data. However, some distortions of the image were observed due to the limitations imposed by the available tunnel which restricted the angular views available to the sensors. Muon geotomography works best when sensors are placed such that they can view the region under study from a range of different angles. The demonstrated ability to perform accurate forward model simulations makes the sensitivity of the technique predictable for specific survey situations. The results demonstrate the potential of muon geotomography for identification and characterization of orebodies located in complex geologic environments. Three-dimensional images from muon geotomography surveys may be used to guide drilling operations toward regions of high-density contrast, thereby significantly reducing costs and environmental impact associated with locating orebodies.
Résumé(Résumé en langage clair et simple, non publié)
L'Initiative géoscientifique ciblée (IGC-4) est un programme géoscientifique fédéral de collaboration qui fournit à l'industrie les connaissances géoscientifiques et les techniques novatrices de prochaine génération dont elle a besoin pour mieux détecter les gîtes minéraux enfouis, réduisant ainsi certains risques liés à l'exploration. La géotomographie muonique permet d'obtenir des images de la distribution de densité sous la surface en utilisant les rayons cosmiques. Puisque ceux-ci sont plus facilement atténués par des objets denses, en mesurant les taux d'atténuation, on pourra cartographier la position de la roche plus dense, laquelle pourrait être associée à des gisements minéraux. Nous avons mesuré le flux de rayons cosmiques dans un site minier sous un gisement connu et l'avons comparé aux résultats obtenus sur une carotte de forage. Le bon accord entre les deux suggère que la géotomographie muonique pourrait servir à localiser et caractériser les corps minéralisés.
GEOSCAN ID294807