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TitreOn the relationship between cathodoluminescence and the chemical composition of scheelite from geologically diverse ore-deposit environments
AuteurPoulin, R S; McDonald, A M; Kontak, D J; McClenaghan, M B
SourceCanadian Mineralogist vol. 54, 5, 2016 p. 1147-1173,
Séries alt.Ressources naturelles Canada, Contribution externe 20182502
ÉditeurAssociation minéralogique du Canada
Documentpublication en série
Mediapapier; en ligne; numérique
ProgrammeSystèmes porphyriques post-orogéniques - Temps et espace, Initiative géoscientifique ciblée (IGC-5)
Diffusé2017 05 30
Résumé(disponible en anglais seulement)
The relationship between cathodoluminescence (CL) response and chemical composition of scheelite from a variety of oredeposit settings (e.g., orogenic Au, skarn, porphyry-related, greisens, VMS) was investigated using SEM-EDS, CL imaging, and LA-ICP-MS techniques. Our detailed study concentrates on five samples of scheelite from a range of ore-deposit settings, including orogenic Au, skarn, VMS, and greisen deposits, but draws on a yet unpublished data base of more than 39 deposits world-wide. Results indicate that the scheelite zonation patterns observed under CL can be useful in discriminating between scheelite arising from differing mineralized environments. Scheelite from orogenic Au deposits exhibits a homogenous CL response in contrast to that from proximal intrusion-related systems, such as porphyries, skarns, and greisens that show a strong oscillatory zonation, with individual zones ranging from < 1 ?m to >300 ?m in width. Results from LA-ICP-MS analyses show significant chemical variations in scheelite with respect to Mo, Sr, As, and ?REE + Y. Maps generated from CL imaging and LA-ICP-MS data reveal a strong negative correlation between the intensity of the CL response in scheelite and Mo content.While enrichments of Sr, As, and ?REE + Y are noted, none exhibit a correlatable effect with CL response. Furthermore, the qualitative Mo and W X-ray maps produced via SEM-EDS correlate with the corresponding LA-ICP-MS maps of the scheelite grain, successively delineating the zonation patterns observed under CL. This work also demonstrates that the combination of CL and LA-ICP-MS mapping is a powerful tool in the discussion of observed CL textures, elemental relationships, mineral growth history, and paragenesis.