| Title | Characteristics of diagenetic and epigenetic sulphides in deformed and metamorphosed Archean carbonaceous metasedimentary rocks of the Timmins-Matheson corridor: establishing a framework for fingerprinting
ore-forming processes in shear zone-hosted orogenic gold systems |
| Download | Download (whole publication) |
| |
| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Pilote, J -L; Jackson, S E ; Mercier-Langevin, P; Dubé, B; Rhys, D |
| Source | Targeted Geoscience Initiative: 2018 report of activities; by Rogers, N (ed.); Geological Survey of Canada, Open File 8549, 2019 p. 33-41, https://doi.org/10.4095/313632  Open Access |
| Year | 2019 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| Related | This publication is contained in Targeted Geoscience
Initiative: 2018 report of activities |
| File format | pdf |
| Province | Ontario |
| NTS | 31M/13; 32D/04; 32D/05; 32D/12; 32D/13; 32E/04; 41P/13; 41P/14; 41P/15; 41P/16; 42A; 42H/01; 42H/02; 42H/03; 42H/04 |
| Area | Timmins; Matheson |
| Lat/Long WENS | -81.5500 -79.6500 49.2167 47.8333 |
| Subjects | economic geology; tectonics; geochemistry; mineralogy; mineral deposits; gold; sulphide deposits; epigenetic deposits; mineral exploration; ore mineral genesis; mineralization; ore controls; mineral
enrichment; tectonic setting; tectonic history; deformation; metamorphism; hydrothermal systems; intrusions; bedrock geology; lithology; metamorphic rocks; metasedimentary rocks; carbonate rocks; argillites; greywackes; igneous rocks; intrusive
rocks; structural features; shear zones; nodules; textural analyses; fluid dynamics; scanning electron microscope analyses; mass spectrometer analysis; petrographic analyses; geochemical analyses; trace element analyses; morphology; isotopic studies;
Archean; Kidd-munro Assemblage; Tisdale Assemblage; Porcupine Assemblage; Timiskaming Assemblage; Blake River Assemblage; Deloro Assemblage; Stoughton-roquemaure Assemblage; Pacaud Assemblage; Bell Creek Deposit; Bradshaw Deposit;
Precambrian |
| Illustrations | geoscientific sketch maps; photographs; photomicrographs; geochemical plots |
| Program | Targeted Geoscience Initiative (TGI-5) Knowledge Management Coordination |
| Program | Targeted Geoscience Initiative (TGI-5) Gold ore systems - System Controls - Time and Space |
| Released | 2019 03 01 |
| Abstract | This research activity investigates the origin of gold-rich (up to approximately 10 ppm) iron sulphide nodules and the timing of gold introduction in Archean carbonaceous metasedimentary rocks near and
distal to orogenic gold mineralization in the Timmins-Matheson area, Ontario. It provides insights into the factors controlling gold enrichment and tests the hypothesis asserting a genetic link between sedimentary sulphides and orogenic gold
deposits. Preliminary textural examination of numerous iron sulphide (e.g. pyrite) nodules hosted in various sedimentary sequences from assemblages, including Kidd-Munro, Tisdale, Porcupine, and Timiskaming, reveals evidence of nucleation and
formation prior to the main regional deformation events. Pyrite grains that are unequivocally metamorphic/hydrothermal in origin (e.g. coarse-grained euhedral porphyroblasts, overgrowths, and cross-cutting stringers) show distinct geo-chemical
signatures compared to the nodules, with lower contents of Sb, Tl, Ag and Au. There are also consistent intra-nodule chemical trends, including, for example, systematic decreases in Au and Ni/Tl from core to rim. These trends are observed across the
region, regardless of the setting of the nodules (i.e. shear-hosted, proximal or distal to mineralization, stratigraphic depths). The systematic core to rim decrease in gold content may reflect increasing pH and/or redox potential of the ambient
fluid during the development of the nodules. Further geochemical and isotopic work is being conducted to better understand the genesis of the gold-rich nodules and any potential genetic link that may exist between orogenic Au mineralization and an
earlier gold enrichment event in the Timmins-Matheson area. |
| Summary | (Plain Language Summary, not published)
The Targeted Geoscience Initiative (TGI) is directed towards providing next generation knowledge and methods to facilitate more effective targeting of
buried mineral deposits. The program aims to enhance the effectiveness of exploration for Canada's major mineral systems by resolving foundational geoscience problems that constrain the geological processes responsible for the liberation metals from
their source region, transportation of these ore metals and control their eventual deposition. TGI supports projects on gold, Ni-Cr-PGE, porphyry-style mineralization, uranium and volcanic- and sedimentary-hosted base metal mineralization ore
systems, with each project divided into subprojects focused on resolving specific knowledge gaps by integrating data and studies from multiple sites across Canada. Herein, we present interim results and interpretations from a selection of the
research activities currently being conducted under the auspices of TGI. |
| GEOSCAN ID | 313632 |
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