Structural Controls on ore body architecture of Volcanogenic Massive Sulphides
Case study: Snow Lake Camp, Manitoba
A PhD Project at the University of Toronto with support from Hudbay Minerals
I am seeking to understand the structural controls of ore body architecture of ancient volcanogenic massive sulphide (VMS) deposits. These deposits are critical sources of energy transition minerals. They also provide unique geodynamic research potential with geological conditions related to hydrothermal, volcanic, and tectonic environments ascertained via paragenetic studies of VMS ore bodies. I hope to leverage my expertise in economic geology and rock mechanics to expand our shared understanding of the processes involved in gold mineralization in deformed and metamorphosed VMS ore lenses. The Snow Lake camp is my primary case study for this research. The VMS ore bodies of Snow Lake are owned and mined by Hudbay Minerals, who are providing in-kind support for this research project. This work is supported by funding from the University of Toronto, Ontario Graduate Scholarship, and iMAGE CREATE. I am supervised by Professor Melissa Anderson (University of Toronto) and co-supervised by Professor Meg Stewart (Mount Royal University).
My work will include a multi-variate statistical analyses of the existing, large, whole-rock geochemical data base from sampled drill core from the Snow Lake camp. These analyses will seek multi-elemental associations with metal mineralization and alteration suites, as well as associated deposit-scale folds and faults in 3D space. The resulting structural and lithogeochemcial 3D model will be field tested with new surface and underground mapping and core logging. Additional analyses will include petrographic studies and LA ICP MS work. Electron Backscattered Diffraction (EBSD) may be employed for microstructual work to better understand metal mobility. Oxygen isotope work may also be conducted to delineate paleohydrothermal upflow zones.
Geochronological work is also planned for this project. To date, none of the host rocks (the Chisel Basin) of the Snow Lake VMS ore bodies have been successfully radiometrically dated. The preliminary results of the statistical analyses and 3D model of Snow Lake have created new sampling targets for minerals (zircons and baddeleyite) for U-Pb dating. A recent research grant from the Society of Economic Geologists will enable isotope dilution-thermal ionization mass spectrometry analyses at the Jack Satterly Geochronology Laboratory.
This research project seeks to answer the most pressing questions in understanding VMS architecture. Defining the roles and scales of structures in primary mineralization, epigenetic enrichment, and metal re-mobilisation may improve the VMS ore genetic model and create new mineral exploration vectoring tools for VMS ore bodies.
The following poster was presented at GAC MAC, 2024, in Brandon Manitoba. A portion of the travel costs to attend this conference, plus costs associated with an underground mapping and core sampling site visit to Snow Lake, was funded by the Mineral Association of Canada Student Travel & Research Grant.
References
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Caté, A., Schetselaar, E., Mercier-Langevin, P., & Ross, P.-S. (2018). Classification of lithostratigraphic and alteration units from drillhole lithogeochemical data using machine learning: A case study from the Lalor volcanogenic massive sulphide deposit, Snow Lake, Manitoba, Canada. Journal of Geochemical Exploration, 188, 216–228.
Cowan, J. (2020). Deposit-scale structural architecture of the Sigma-Lamaque gold deposit, Canada—insights from a newly proposed 3D method for assessing structural controls from drill hole data. Mineralium Deposita, 55(2), 217–240.
Friedman, J. H. (2001). Greedy Function Approximation: A Gradient Boosting Machine. The Annals of Statistics, 29(5), 1189–1232.
Friesen, V. C., DeWolfe, Y. M., & Gibson, H. L. (2021). Volcanic reconstruction and geochemistry of the Powderhouse formation in the Paleoproterozoic VMS-hosting Chisel sequence, Snow Lake, Manitoba, Canada. Canadian Journal of Earth Sciences, 58, 247–267.
Fresia, B., Ross, P.-S., Gloaguen, E., & Bourke, A. (2017). Lithological discrimination based on statistical analysis of multi-sensor drill core logging data in the Matagami VMS district, Quebec, Canada. Ore Geology Reviews, 80, 552–563.
Stewart, M. S., Lafrance, B., & Gibson, H. L. (2018). Early thrusting and folding in the Snow Lake camp, Manitoba: tectonic implications and effects on volcanogenic massive sulfide deposits. Canadian Journal of Earth Sciences, 55, 935–957.
The following poster was presented at GAC MAC 2023, in Sudbury, Ontario.