| Titre | Scheelite geochemical signatures and potential for fingerprinting ore deposits |
| Télécharger | Téléchargements |
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| Licence | Veuillez noter que la Licence du gouvernement
ouvert - Canada remplace toutes les licences antérieures. |
| Auteur | Poulin, R S; McDonald, A M; Kontak, D J; McClenaghan, M B |
| Source | TGI 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. 317-326, https://doi.org/10.4095/296473  Accès ouvert |
| Liens | Canadian Database of Geochemical Surveys, downloadable files
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| Liens | Banque de données de levés géochimiques du Canada,
fichiers téléchargeables
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| Image |  |
| Année | 2015 |
| Éditeur | Ressources naturelles Canada |
| Document | dossier public |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/296473 |
| Media | en ligne; numérique |
| Référence reliée | Cette publication est contenue dans TGI 4 -
Intrusion Related Mineralisation Project: new vectors to buried porphyry-style mineralisation |
| Référence reliée | Cette publication est reliée à Scheelite
geochemical signatures and potential for fingerprinting ore deposits |
| Formats | pdf |
| Sujets | scheelite; gisements minéraux; arsenic; molybdène; géochimie des terres rares; éléments d'indice; géochimie; géologie économique |
| Illustrations | photographies; graphiques |
| Programme | Initiative géoscientifique ciblée (IGC-4) Étude des gîtes porphyriques |
| Diffusé | 2015 06 11; 2023 03 17 |
| Résumé | (disponible en anglais seulement)
Scheelite (CaWO4) is a common accessory mineral found in a variety of geologically diverse ore-deposit settings, including vein/stockwork, skarn, porphyry,
epithermal and strata-bound. As part of the Geological Survey of Canada's (GSC) Targeted Geoscience Initiative (TGI 4) program, the project reported on here was developed to investigate the potential for discriminating scheelite originating from
different ore-deposit types. The study investigated whether crystal-chemical features of scheelite, such as cathodoluminescence (CL), trace-element chemistry, and isotopic signature (O), could be used independently or together as deposit-type
discriminators, thereby assessing the feasibility of using scheelite for provenance studies in regional till-sampling programs. Here we report on the geochemical data obtained using the LA ICP-MS method on scheelite to see if it could be used to
geochemically fingerprint its environment of formation. The samples used come from the granite-related, world-class Sisson W-Mo porphyry-type deposit, NB, along with forty-one scheelite samples from a range of deposit types that constituted the suite
used in the broader crystal-chemical study. The protocol used was twofold: (1) collect data using line traverses and integrate the data over intervals showing uniform chemistry; and (2) generate element maps for a select few scheelite grains which
displayed complex zoning patterns revealed through CL imaging. Despite using an extensive element list (e.g., LILEs, alkalies, transition metals, HFSEs), only Mo, As and the REEs, which follow crystal growth patterns, showed significant levels of
elemental enrichment (i.e., > 1.0 ppm). The correlation of As and Mo indicate only a small intra-deposit variance, but the large inter-deposit variation offers the potential to use this element pair to discriminate deposit types. The results for the
REEs indicate: (1) a lack of apparent correlation between REEs and the type of CL observed despite previous suggestions to the contrary; (2) considerable variation in the ?REEs amongst the sample suite used; (3) most samples are dominated by a single
chondrite-normalized (CN) pattern, but rarely a second pattern is present; although the type of CN REE patterns vary (e.g., convex MREE, LREE enrichment), there is a similarity among deposit types; and 5) both positive and negative Eu anomalies are
observed. These initial results suggest that the minor and trace-element chemistry of scheelite along with CL imaging, may offer the potential to discriminate and identify deposit types based on its geochemical fingerprinting. |
| Sommaire | (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. Ce volume résume les activités de recherche
effectuées dans le cadre du projet de minéralisation lié à des intrusions de l'Initiative géoscientifique ciblée 4 qui était axé sur des systèmes minéralisés porphyriques associés aux dépôts de Cu et de Cu-Mo dans le centre-sud de la
Colombie-Britannique et aux dépôts de Sn-W-Mo-In au Nouveau-Brunswick, en Nouvelle-Écosse et à Terre-Neuve-et-Labrador. |
| GEOSCAN ID | 296473 |
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