| Title | Petrographic observations and evaporate mound analysis of quartz-hosted fluid inclusions hosted by granitoid samples from the South Mountain Batholith, Nova Scotia: an exploration tool for vectoring
towards mineralised areas in intrusive rocks |
| Download | Downloads |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Tweedale, F; Hanley, J J; Kontak, D J; Rogers, N |
| Source | TGI 4 - Intrusion Related Mineralisation Project: new vectors to buried porphyry-style mineralisation; by Rogers, N (ed.); Geological Survey of Canada, Open File 7843, 2015 p. 79-99, https://doi.org/10.4095/296467  Open Access |
| Links | Canadian Database of Geochemical Surveys, downloadable
files
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| Links | Banque de données de levés géochimiques du Canada,
fichiers téléchargeables
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| Image |  |
| Year | 2015 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| Related | This publication is contained in TGI 4 - Intrusion Related
Mineralisation Project: new vectors to buried porphyry-style mineralisation |
| File format | pdf |
| Province | Nova Scotia |
| NTS | 21A; 11D; 11E |
| Lat/Long WENS | -66.0000 -63.5000 45.0000 43.0000 |
| Subjects | economic geology; metallic minerals; igneous and metamorphic petrology; porphyry deposits; porphyry copper; mineral exploration; mineralization; alteration; tungsten; molybdenum; tin; bismuth; mineral
deposits; intrusive rocks; granitic rocks; fluid inclusions; quartz; metallogeny; petrographic analyses; granodiorites; petrogenesis; copper; gold; South Mountain Batholith |
| Illustrations | location maps; photographs; cross-sections; photomicrographs; plots; ternary diagrams |
| Program | Targeted Geoscience Initiative (TGI-4) Intrusion/Porphyry Ore Systems |
| Released | 2015 06 11; 2023 03 17 |
| Abstract | The ca. 380 Ma South Mountain Batholith (SMB) of Nova Scotia is a large (ca. 7,300 km2), mesozonal granitoid intrusion that consists of 13 coalesced plutons of granodiorite to leucomonzogranitic
composition which host a variety of mineralised zones (e.g., Sn-Zn-Cu-Ag, Mo, Mn-Fe-P, U, Cu-Ag). Given the hydrothermal nature of this mineralisation, it is expected that a fingerprint of the mineralizing fluids might be manifested both
petrographically and by the chemistry of secondary, quartz-hosted fluid inclusions in the granites on a scale equal to or larger than the mineralised centres. In order to assess the potential of using the petrographic and chemical fingerprints as
vector for exploration, a study integrating both these methods was investigated. The protocol involved in the study included the following: (1) completing a detailed petrographic study of hundreds of archived thin section samples that focused on the
extent and degree of alteration that reflect fluid-rock interaction. The indices included: (i) type and abundance of perthite, (ii) chloritic alteration of biotite, (iii) plagioclase alteration, (iv) amount of secondary white mica, and (v) abundance
of secondary fluid inclusions in quartz; and (2) determining the fluid chemistry of quartzhosted fluid inclusions in samples (n = 66) collected from the SMB. For this study, a detailed protocol was developed to address specific analytical
considerations, including decrepitation temperature, oven versus stage heating, EDS calibration, EDS acquisition time, representative sampling and raster versus point mode of analysis. Thus, in this study, quartz chips were heated to 500ºC and a
maximum of 16 mounds per sample were analysed (60 seconds) in raster mode, the latter to circumvent chemical variation related to elemental fractionation during mound formation. To date, the results indicate that the fluids from Phase 1 samples are
dominated by a Na-F-Cl-Ca fluid. In contrast, fluids from Phase 2 samples are dominated by two fluid inclusion populations: a Na-K fluid and a F-Na-Cl-Ca fluid. |
| Summary | (Plain Language Summary, not published)
The Targeted Geoscience Initiative (TGI-4) is a collaborative federal geoscience program that provides industry with the next generation of geoscience
knowledge and innovative techniques to better detect buried mineral deposits, thereby reducing some of the risks of exploration. This volume summarises research activities completed under the TGI 4 Intrusion Related Mineralisation Project that
focused on porphyry-style ore systems related to the Cu- and Cu-Mo deposits of South-Central British Columbia and the Sn-W-Mo-In deposits in New Brunswick, Nova Scotia and Newfoundland. |
| GEOSCAN ID | 296467 |
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