| Title | Fluids and ore forming processes in orogenic gold deposits in Newfoundland, eastern Canada: evidence from fluid inclusion and stable isotope studies |
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| Author | Conliffe, J; Sandeman, H A I; Honsberger, I W ; Guillaume, B; Laflamme, C; Wilton, D |
| Source | Atlantic Geoscience vol. 59, 2023 p. 76-77, https://doi.org/10.4138/atlgeo.2023.003  Open Access |
| Links | Online - En ligne
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| Image |  |
| Year | 2023 |
| Alt Series | Natural Resources Canada, Contribution Series 20220661 |
| Publisher | Atlantic Geoscience |
| Document | serial |
| Lang. | English |
| Media | paper; digital; on-line |
| File format | pdf |
| Province | Newfoundland and Labrador |
| Subjects | Science and Technology; metallic minerals; gold; mineral deposits |
| Program | Targeted Geoscience Initiative (TGI-6) Ore systems |
| Released | 2023 05 03 |
| Abstract | Newfoundland is a major emerging gold district containing numerous gold occurrences associated with Paleozoic crustal-scale fault systems. These occurrences have characteristics typical of orogenic gold
deposits, such as association with crustal-scale faults, syntectonic rock sequences, and lower greenschist- to amphibolite-facies metamorphism. However, there are significant variations in mineralization styles and settings between individual gold
occurrences, including host lithologies, metal associations and sources, and inferred mineralization depths. This study investigates variations in mineralizing fluids and ore-forming processes in central Newfoundland, based on fluid inclusion and
preliminary sulphur isotope data from a number of gold occurrences representing a diverse range of geological settings. Fluid inclusion studies have shown that mineralizing fluids are moderate to high temperature (250 to 350°C), low-salinity (< 10
wt% eq. NaCl) aqueous carbonic fluids, which are considered typical of orogenic gold deposits. However, there are significant inter-deposit variations (e.g. XCO2, CO2:CH4) that are likely related to fluid unmixing and the geochemical influence of the
host lithologies. Isochoric modelling suggests different depths of mineralization for gold occurrences across central Newfoundland, ranging from relatively shallow epizonal mineralization in the Gander area (e.g. Queensway, Moosehead, Kingsway) to
deeper mesozonal mineralization in deposits to the southwest (e.g. Valentine Lake, Wilding Lake). In-situ sulphur isotope analyses of sulphides associated with gold mineralization can provide insights into ore deposition processes as well as the
source of sulphur in orogenic gold deposits. Preliminary data from along the central Newfoundland orogenic gold district show significant inter-deposit variability. Future research will include more fluid inclusion studies along with in situ sulfur
isotope and trace element analyses, which will be used to better constrain ore fluids, sulphur and metal sources, and gold precipitation mechanisms. |
| Summary | (Plain Language Summary, not published)
This contribution presents new data regarding the source of fluids that precipitated gold throughout central Newfoundland. |
| GEOSCAN ID | 331695 |
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