| Titre | Trace elements and oxygen isotope of quartz from the Nashwaak Granite and dykes, and quartz veins related to the Sisson Brook W-Mo-Cu deposit, west-central New Brunswick |
| Télécharger | Téléchargement (publication entière) |
| Auteur | Zhang, W; Lentz, D R; McFarlane, C R M; Thorne, K G |
| 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. 475-491, https://doi.org/10.4095/296484 |
| Année | 2015 |
| Éditeur | Ressources naturelles Canada |
| Document | dossier public |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/296484 |
| Media | en ligne; numérique |
| Référence reliée | Cette publication est contenue dans Rogers, N;
(2015). TGI 4 - Intrusion Related Mineralisation Project: new vectors to buried porphyry-style mineralisation, Commission géologique du Canada, Dossier public 7843 |
| Référence reliée | Cette publication est reliée à Lang, J R; Duncan,
R; Lentz, D; Zhang, W; Bustard, A; McFarlane, C R M; Thorne, K G; (2014). Geological and structural controls on hydrothermal alteration and W-Mo mineralization in the Sisson deposit, New Brunswick, L'Association géologique du Canada-L'Association
minéralogique du Canada, Réunion annuelle conjointe, Recueil des résumés vol. 37 |
| Formats | pdf |
| Province | Nouveau-Brunswick |
| SNRC | 21J/02N; 21J/03NE; 21J/06SE; 21J/07SW |
| Lat/Long OENS | -67.1667 -66.8333 46.5000 46.1667 |
| Sujets | analyses des éléments en trace; géochimie des éléments en trace; éléments en trace; isotopes d'oxygène; gisements porphyriques; cuivre porphyrique; prospection minière; minéralisation; tungstène;
molybdène; cuivre; or; granites; filons rocheux; Granite de Nashwaak ; géologie économique; géochimie; Paléozoïque; Dévonien; Silurien; Ordovicien |
| Illustrations | location maps; photomicrographs; photographs; plots |
| Consultation | |
| Bibliothèque de Ressources naturelles Canada - Ottawa (Sciences de la Terre) |
| |
| Programme | Étude des gîtes porphyriques, Initiative géoscientifique ciblée (IGC-4) |
| Liens | Canadian Database of Geochemical Surveys, downloadable files
|
| Liens | Banque de données de levés géochimiques du Canada,
fichiers téléchargeables
|
| Diffusé | 2015 06 11 |
| Résumé | (disponible en anglais seulement)
The Sisson Brook W-Mo-Cu deposit, situated in west-central New Brunswick, is hosted by Cambro- Ordovician volcanic and sedimentary rocks of the Miramichi and
Tetagouche groups. These rocks have been intruded by the Early Devonian Howard Peak diorite-gabbro, Nashwaak Granite, a phaneritic felsic dyke swarm, and a distinctively younger Late Devonian porphyritic felsic dyke. In order to understand the magma
evolution history, the textural and geochemical characteristics of quartz phenocrysts from these felsic rocks were analyzed with the aid of SEM-cathodoluminescence (CL), laser ablation inductively coupled plasma mass spectrometry (LA ICPMS), and
secondary ion mass spectrometry (SIMS).
Four intrusive granitic units in the Sisson Brook deposit area: (1) medium-grained, equigranular two-mica granite with brown biotite that is slightly altered to chlorite; (2) biotite- granite with ca. 20 %
greenish brown biotite and accessory zircon, apatite, monazite, magnetite, titanite, sulfide and ilmenite; (3) biotite-granite dykes with similar mineralogical features to the biotite-granite; and (4) porphyry dykes with phenocrysts consisting of
approximately 23 % plagioclase, 10 % quartz, 8 % biotite, and 7 % K-feldspar.
Quartz phenocyrsts in two-mica granite and biotite-granite plutonic phases is unzoned indicating that it formed at relatively stable magma chamber. Quartz dissolution
textures in the dyke phases might be caused by cooling from 600°C to 300°C at pressure below 1 Kbar. Quartz phenocrysts in porphyry dyke samples are oscillatory-zoned. With the assumption that the activity of Ti in these magmas is 0.8 (based on the
presence of ilmenite rather than rutile), Ti-In-quartz geothermometry indicates that the porphyry dykes formed at a temperature above 675°C, twomica granite and biotite-granite plutons formed at 600°C to 700°C, and the biotite-granite dykes formed at
slightly below 600°C. Higher Ge/Ti ratios reflect greater degrees of magma differentiation. This ratio increases from porpyrhy dykes, two-mica granite and biotite-granite pluton phases to biotite dykes. The highest Al content of quartz measured in
two-mica granite is consistent with the highest aluminium saturation index of its whole rock. The oxygen isotope of quartz is from 8-8.5 perthousand for biotite-granite, 9-10 perthousand for biotite dykes and porphyry dykes, and 10-10.5 perthousand
for the two-mica granites. The later mineralization quartz veins in the dykes have oxygen isotope values between 8.5 perthousand to 9.5 perthousand, indicating the hydrothermal fluids related to the Sisson Brook deposit are dominantly magmatic
fluids. |
| GEOSCAN ID | 296484 |
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