| Titre | Magmatic mica and its potential as an indicator of magma fertility in the granitoids of New Brunswick |
| Télécharger | Téléchargements |
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| Licence | Veuillez noter que la Licence du gouvernement
ouvert - Canada remplace toutes les licences antérieures. |
| Auteur | Azadbakht, Z ;
Lentz, D R; McFarlane, C R M |
| 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. 561-562, https://doi.org/10.4095/296491  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/10.4095/296491 |
| 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 Magmatic mica and
its potential as an indicator of magma fertility in the granitoids of New Brunswick |
| Formats | pdf |
| Province | Nouveau-Brunswick |
| SNRC | 21G; 21H; 21I; 21J; 21O; 21P |
| Lat/Long OENS | -68.0000 -64.0000 48.0000 45.0000 |
| Sujets | gisements porphyriques; cuivre porphyrique; prospection minière; minéralisation; biotite; granodiorites; gisements minéraux hydrothermaux; altération hydrothermale; tungstène; molybdène; or; antimoine;
roches magmatiques; roches intrusives; roches ignées; gisements filoniens; magmatisme; méthodes analytiques; amphibole; differentiation magmatique; gîtes magmatiques; uranium; mica; tantale; lithium; Orogenèse Acadienne; géologie économique;
pétrologie ignée et métamorphique; géochimie; Paléozoïque; Dévonien |
| Illustrations | cartes de localisation; graphiques; photomicrographies |
| Programme | Initiative géoscientifique ciblée (IGC-4) Étude des gîtes porphyriques |
| Diffusé | 2015 06 11; 2023 03 17 |
| Résumé | (disponible en anglais seulement)
The mineralized intrusions of New Brunswick are related to crustal growth processes that occurred during Acadian Orogeny, post Acadian uplift, and Neo-Acadian
Orogeny. They were emplaced pre-, syn-, late-, and post-tectonically between 423 and 360 Ma. These intrusions have affinities ranging from primitive to highly evolved A-, S-, and I-types granitoids, and are associated with Sn, Ta, Li, Sb, W, Mo, Cu,
and Au, as well as basemetals and U mineralization.
Biotite crystallizes over a wide range of conditions and reacts very sensitively to physiochemical conditions of the magma; this sensitivity makes mica a great mineral for identifying the
petrogenetic, mineralization, and alteration processes of the host granitic rocks. The following features make biotite a valuable probe of magma composition: 1) it is the most important reservoir of any excess aluminium in granites that do not
contain modal garnet, cordierite, or the Al2SiO5 polymorphs; therefore, it directly reflects the peraluminosity of the host magma in such rocks; 2) it is the most readily available indicator of oxidation state; and 3) it can provide information about
the F and Cl content of the magma. Mineralized and barren rocks are characterized by different chemical variations in biotite. For instance, mineralized biotite is characterized by lower Mg and Ti contents relative to biotite from barren rocks; they
also have higher amount of Al comparing to biotite from barren phases.
Several studies have shown that biotite, continuously equilibrates with the host liquids. Therefore, core-to-rim study of this mineral and its compositional zoning may provide
a record of magma evolution so that the origin and evolution of granitoids can be discerned. Furthermore, the chemical composition and the colour of this mineral strongly reflects the tectonic origin of its host. For instance, the bright red colour
of biotite indicates peraluminous collisional granitic pluton and reflects a high total Fe content with low Fe3+/(Fe2+ + Fe3+) and probably the presence of Ti4+. In part this study aims to calculate fluoride and chloride activity of aqueous fluids
based on F and Cl contents in the minerals containing hydroxyl and halogens determined by combined electron microprobe and LA ICP-MS analysis. The final data will be compared to the whole rock geochemistry. These results are expected to help
constrain crystallization conditions, volatile exsolution and fluorine-chlorine activity of fluids associated with these intrusions.
They should also indicate the degree of subsolidus re-equilibration via various geothermobarometry
techniques. |
| 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 | 296491 |
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