CHARACTERIZATION OF TAILINGS DUST FROM TWO ABANDONED MINE SITES: EFFECTS ON NEARBY SURFACE WATERS AND EVALUATION OF DUST SAMPLING METHODS by Amy Elizabeth Cleaver A thesis submitted to the Department of Geological Sciences and Geological Engineering In conformity with the requirements for the degree of Master of Science Queen’s University Kingston, Ontario, Canada June, 2020 Copyright © Amy Elizabeth Cleaver, 2020 Abstract Canada’s climate is warming and as a result the hydrological cycle is expected to become more intense, with rainfall concentrated in extreme events with longer dry spells. Consequently, dry tailings may be more likely to blow into nearby surface waters. This research is an investigation into the geochemical effects of tailings dust on nearby surface waters and evaluates dust sampling methods used to investigate seasonal trends. During this study, two abandoned mine sites in Nova Scotia, Canada were investigated: Stirling Zn-Pb and Goldenville Au mine. At Stirling, tailings were sieve to <63µm as a proxy for dust and analyzed to determine metal concentrations and identify primary and secondary metal-bearing phases. Metal-hosting phases identified include sphalerite, smithsonite, aurichalcite, hydrohetaerolite, goethite. tennantite, galena, cerussite, Pb-Mn phases, and chalcopyrite. Shake flask tests were conducted to investigate dust solubility in simulated stream waters (pH=7). Results indicate that dust particles are partially water soluble in the shake flask test and that sphalerite, cerussite and chalcopyrite are likely the main sources of Zn, Pb and Cu in the shake flask leachate, based on calculated saturated indices and mass balance. Analyses of stream water indicate similar conditions (pH, Eh, etc.) and saturation indices compared to shake flask tests, and therefore provide reasonable insight for processes occurring the field. Dust was also sampled using a variety of different methods to identify the most suitable method for seasonal sampling. These included passive dry deposition collectors (PAS-DDs), high volume total suspended particle (TSP) sampler (HVAS), dust deposition gauges (DDGs), and lichen. Results indicate that Pas-DDs with a glass fiber filters (GFF) and dust deposition gauges likely underestimate dust deposition. In comparison, Pas-DDs with a polyurethane foam disk (PUF) efficiently accumulate dust. However, PUFs had additional challenges including metal(loid)s within the filters themselves, difficulty obtaining stable weights, and potential dust collection from the sides and bottom. Despite difference between dust sampling methods, it was ii observed that dust deposition was highest in the winter months due to higher wind speeds. Future dust generation remains difficult to predict due to the unknown combined effect of changes in temperature, precipitation, evaporation, and wind speed. iii Acknowledgements First and foremost, I would like to thank my co-supervisors, Heather Jamieson and Philippa Huntsman, for providing me with this wonderful opportunity. Heather, your passion as a scientist is truly inspirational. I will miss our thought provoking conversations which always had a perfect balance of guidance, yet still challenged me as a scientist. Philippa, your genuine interest in this project is undeniable. I always enjoyed our lengthy conversations in the field, phone calls and visits to Ottawa. You are both amazing role-models in terms of family-work life, I admire both of you for having very successful careers and raising families while sometimes travelling the globe. To the Jamieson Research group (Chris, Clare, Sean, Brent, Kat, et al.), thank you for all your support, company at conferences, and late nights at the synchrotron. You will all do great things. To my peers in the Queen’s Geology Department, you are a supportive group of people and you all made my experience at Queen’s one to remember. To Rob Beaudion, thank you for everything you did, including organizing field equipment, driving to Nova Scotia, sample preparation, sending samples to the lab and not complaining when asked to re-run them. Both field work and lab work would not have been possible without your help. To Carrie Rickwood, thank you for your help organizing this project, assistance in the field, and sharing your lichen data. To the CanmetMINING’s Chemical Intelligence Analytical Laboratory, thank you for all the sample analyses, especially Yvonne Boucher for completing the digests and Ruipang Wang for helping with QA/QC related queries. To Agatha Dobosz, thank you for spending time with me in the SEM lab, and always calling me out on my lack of computer knowledge. To Brian Joy, thanks for guiding me through my microprobe analyses, even when particle size was not on our side. Thanks to Matt Newville and Tony Lanzirotti for all their help during those long days at the synchrotron. Special thanks to iv Stephanie De Sisto, Rob Beaudion, Mike Parsons, Peter White, Jessica Renaud and Carrie Rickwood for your help in the field. Lastly, I would like to thank my family and friends who have been so supportive. And my wonderful partner Michael for helping me even when things got hard. v Table of Contents Abstract ............................................................................................................................................ ii Acknowledgements ......................................................................................................................... iv List of Figures .................................................................................................................................. x List of Tables ................................................................................................................................. xii List of Abbreviations .................................................................................................................... xiv List of Minerals ............................................................................................................................ xvii Chapter 1 Introduction and Background .......................................................................................... 1 1.0 Introduction ............................................................................................................................ 1 1.1 Background on Stirling Mine ................................................................................................. 4 1.1.1 Regional Geology of Stirling Mine ................................................................................. 4 1.1.2 History of Stirling Mine .................................................................................................. 6 1.1.3 Environmental Characterization of Stirling Mine ........................................................... 9 1.2 Background on Goldenville ................................................................................................. 11 1.2.1 Regional Geology of Goldenville ................................................................................. 11 1.2.2 History of Goldenville .................................................................................................. 13 1.2.3 Environmental Characterization of Goldenville ........................................................... 15 1.3 Climate Change .................................................................................................................... 16 1.4 Tailings Dust ........................................................................................................................ 18 1.4 Thesis Organization ............................................................................................................. 19 1.5 References ............................................................................................................................ 20 Chapter 2 Tailings Dust Characterization and Impacts on Surface Water Chemistry at Stirling Mine, Nova Scotia ......................................................................................................................... 25 2.0 Abstract ................................................................................................................................ 25 2.1 Introduction .......................................................................................................................... 26 2.1.1 Study Location .............................................................................................................. 27 2.2 Methods ............................................................................................................................... 28 2.2.1 Field Sampling and Sample Preparation ....................................................................... 28 2.2.2 Sieved Tailings Samples ............................................................................................... 31 2.2.2.1 Elemental Analysis ................................................................................................ 31 2.2.2.2 Mineralogical Analysis .......................................................................................... 32 2.2.2.3 Simulated Surface Water Shake Flask Test ........................................................... 33 2.2.3 Water Analysis .............................................................................................................. 34 vi 2.2.4 Passive Dry Deposition Collector (Pas-DDs) Filters .................................................... 35 2.2.4.1