University of Calgary PRISM: University of Calgary's Digital Repository Graduate Studies The Vault: Electronic Theses and Dissertations 2013-01-08 The geochemistry of saline springs in the Athabasca oil sands region and their impact on the Clearwater and Athabasca rivers Gue, Anita Gue, A. (2013). The geochemistry of saline springs in the Athabasca oil sands region and their impact on the Clearwater and Athabasca rivers (Unpublished master's thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/28159 http://hdl.handle.net/11023/400 master thesis University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Downloaded from PRISM: https://prism.ucalgary.ca UNIVERSITY OF CALGARY The geochemistry of saline springs in the Athabasca oil sands region and their impact on the Clearwater and Athabasca rivers by Anita Eleanor Gue A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE DEPARTMENT OF GEOSCIENCE CALGARY, ALBERTA DECEMBER, 2012 © Anita Eleanor Gue 2012 ii UNIVERSITY OF CALGARY FACULTY OF GRADUATE STUDIES The undersigned certify that they have read, and recommend to the Faculty of Graduate Studies for acceptance, a thesis entitled “The geochemistry of saline springs in the Athabasca oil sands region and their impact on the Clearwater and Athabasca rivers” submitted by Anita Eleanor Gue in partial fulfilment of the requirements for the degree of Master of Science. ________________________________________________ Co-supervisor, Bernhard Mayer, Geoscience ________________________________________________ Co-supervisor, Stephen Grasby, Geoscience ________________________________________________ Edwin Cey, Geoscience ________________________________________________ Michael Wieser, Physics & Astronomy 17 December 2012 Date iii Abstract The geochemistry of saline springs discharging from Devonian carbonate rocks into the Clearwater and Athabasca rivers in northeastern Alberta was characterized using major ions, trace elements, dissolved gases, and PAHs. In addition, stable isotope analyses of H2O, SO4, DIC, Sr, and Cl were used to trace the provenance of spring waters, dissolved solutes, and subsurface processes affecting water chemistry. Spring waters were found to contain Laurentide glacial meltwater, which was supported by radioisotope analyses. The high salinity of the springs was found to be mainly due to evaporite and carbonate dissolution in the subsurface. Spring waters have been affected by bacterial sulfate reduction, methanogenesis, and methane oxidation. Trace elements and some PAHs were present in low concentrations, the origins of which did not seem to be weathering of bitumen. The total discharge of saline groundwater into the rivers over the study reach was estimated using a Cl isotope mass balance approach, which revealed that saline groundwater accounts for only a very small proportion of the annual mass flux in the rivers of trace elements and PAHs, but accounts for a higher proportion of major ions, particularly in the Clearwater River. iv Acknowledgements Many thanks to my two supervisors, Bernhard Mayer and Stephen Grasby, for providing me with such an interesting project and for your generous support along the way. Thanks also for the patience and trust you showed when I left to work in Yellowknife partway through writing this thesis. Thanks also to the fine folks at the Applied Geochemistry Group (Mike, Maurice, Jack) and the Isotope Science Laboratory (Mike, Steve, Jesusa, Nenita) at the University of Calgary for your assistance with lab analyses and your cheerful question answering. Thanks to Bernadette Prömse for assistance in the field and for many laughs. I would also like to acknowledge my colleagues at Environment Canada for their support during my education leave and their encouragement when I returned to work with a thesis to finish. My sisters in geochemistry - Leslie, Leanne, Bernadette – thanks for making my time in Calgary so fun, for the moral support, and for all the adventures both at the university and beyond. Katie, sister on this crazy journey of life, your friendship made all the difference. My dear friends in Yellowknife, your support along the way kept me going through the thick and the thin. Finally, a big thanks to my family for loving encouragement throughout. v Dedication In memory of Aunty Lillian, not because she cared about geochemistry but because she cared about me. Our two years together in Calgary was a blessing. vi Table of Contents Approvals Page.................................................................................................................ii Abstract ............................................................................................................................ iii Acknowledgements........................................................................................................ iv Dedication..........................................................................................................................v Table of Contents ............................................................................................................ vi List of Tables.....................................................................................................................ix List of Figures and Illustrations.....................................................................................xi List of Plates................................................................................................................... xiv CHAPTER ONE: INTRODUCTION .............................................................................1 1.1 Objective...................................................................................................................3 1.2 Oil sands background ............................................................................................3 1.3 Study area ................................................................................................................5 1.3.1 Climate and vegetation..................................................................................7 1.3.2 Quaternary geomorphology.........................................................................7 1.3.3 Geologic setting ..............................................................................................9 1.3.4 Hydrogeologic setting .................................................................................13 1.4 Previous studies of springs .................................................................................16 CHAPTER TWO: METHODS ......................................................................................19 2.1 Sampling locations ...............................................................................................19 2.2 Field methods........................................................................................................20 2.3 Chemical analyses ................................................................................................21 2.3.1 Major ions......................................................................................................21 2.3.2 Dissolved organic carbon (DOC) ...............................................................22 2.3.3 Trace elements ..............................................................................................22 2.3.4 Polycyclic aromatic hydrocarbons (PAHs)...............................................23 2.3.5 Dissolved gas composition .........................................................................23 2.4 Stable isotope analyses.........................................................................................24 2.4.1 δ18O and δ2H of water ..................................................................................24 2.4.2 !34S and δ18O of sulfate.................................................................................24 2.4.3 !13C of dissolved inorganic carbon (DIC) .................................................25 2.4.4 δ13C and !2H of dissolved methane............................................................25 2.4.5 !37Cl ................................................................................................................26 2.4.6 87Sr/86Sr...........................................................................................................26 2.5 Radioisotope analyses..........................................................................................26 2.5.1 Tritium (3H) ...................................................................................................27 2.5.2 Radiocarbon (14C) .........................................................................................27 2.6 QA/QC ..................................................................................................................27 CHAPTER THREE: RESULTS .....................................................................................29 3.1 Field measurements .............................................................................................29 3.1.1 Spring waters ................................................................................................29 3.1.2 River waters