Western University Scholarship@Western Electronic Thesis and Dissertation Repository 9-4-2014 12:00 AM The Late Quaternary Paleolimnology of Lake Ontario Ryan Hladyniuk The University of Western Ontario Supervisor Dr. Fred J. Longstaffe The University of Western Ontario Graduate Program in Geology A thesis submitted in partial fulfillment of the equirr ements for the degree in Doctor of Philosophy © Ryan Hladyniuk 2014 Follow this and additional works at: https://ir.lib.uwo.ca/etd Part of the Geochemistry Commons Recommended Citation Hladyniuk, Ryan, "The Late Quaternary Paleolimnology of Lake Ontario" (2014). Electronic Thesis and Dissertation Repository. 2401. https://ir.lib.uwo.ca/etd/2401 This Dissertation/Thesis is brought to you for free and open access by Scholarship@Western. It has been accepted for inclusion in Electronic Thesis and Dissertation Repository by an authorized administrator of Scholarship@Western. For more information, please contact [email protected]. THE LATE QUATERNARY PALEOLIMNOLOGY OF LAKE ONTARIO (Thesis format: Integrated Article) by Ryan Hladyniuk Graduate Program in Earth Sciences A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy The School of Graduate and Postdoctoral Studies The University of Western Ontario London, Ontario, Canada © Ryan Hladyniuk 2014 Abstract We examined the oxygen isotopic composition of biogenic carbonates, carbon and nitrogen abundances and isotopic compositions of bulk organic matter (OM), and the abundances and carbon isotopic compositions of individual n-alkanes (C17 to C35) for samples from three, 18 m long sediment cores from Lake Ontario in order to: (i) assess how changing environmental parameters affected the hydrologic history of Lake Ontario, and (ii) evaluate changes in organic productivity and sources since the last deglaciation. Knowledge of the hydrologic and ecological behaviour of the Lake Ontario basin during past climate change provides insight into its future sensitivity. During the glacial period, the average lakewater oxygen- isotope composition was –17.5 ‰ (VSMOW), which indicates a significant glacial meltwater contribution. Higher abundances of mid-chain n-alkanes (C23 and C25) with carbon-isotope compositions of –32.5 ‰ (VPDB) record allochthonous OM input, notwithstanding low bulk C/N ratios that normally indicate lacustrine productivity. These results suggest a degraded source, perhaps OM associated with clay minerals. Glacial retreat facilitated proliferation of terrestrial vegetation, as recorded in higher abundances of long-chain (terrestrial) n-alkanes (C27, C29, C31). Cessation of glacial meltwater supply is marked by an increase in lakewater oxygen-isotope composition to ~ –12 ‰ by 13,000 cal BP. This increase was interrupted by a final inflow of low-18O glacial meltwater that lasted ~500 years. Rerouting of the upper Great Lakes caused Lake Ontario to become hydrologically closed from 12,300 to 8,300 cal BP. The lakewater oxygen-isotope composition increased to –7 ‰ because of the end of glacial meltwater supply, and climate-related increases in evaporation and the oxygen- isotope composition of precipitation. A steady increase in terrestrial n-alkane abundances and their carbon-isotope compositions (–31 to –29 ‰) signified plant growth under water- stressed conditions until ~8,000 cal BP. Transition to a wetter climate (6,800 cal BP) and return of upper Great Lakes water supply (~5,300 cal BP) caused lake levels to rise. A decrease in carbon-isotope composition (~2 ‰) in all aquatic n-alkanes during this time signifies a change in the lacustrine carbon pool, whereas a decrease in the carbon-isotope composition of terrestrial n-alkanes signifies relief from more arid conditions. ii Keywords Great Lakes, Lake Ontario, paleolimnology, stable isotopes, ostracodes, clams, organic matter, n-alkanes, glacial meltwater, primary productivity, environmental change, Pleistocene, Holocene iii Epigraph Meltwaters did rush to the sea They say – from Lake Agassiz And that made it cold We are constantly told But the pathways aren’t shown to me! –FJL iv Dedication This thesis is dedicated to my parents, Zeferina and Peter Hladyniuk. v Acknowledgments He who tops the list of acknowledgments is my supervisor Fred Longstaffe. Throughout the past 6 years, Fred has exemplified what it is to be a great supervisor. He offers creative academic ideas, encouragement towards research, virtually limitless patience and the ability to extend your mind in areas you never thought possible. Fred is also an excellent role model; his leadership has advanced my personal professional development skills while maintaining the highest ethical (academic and personal) integrity. Without Fred, I would not have been able to participate in the numerous conferences and field trips I attended. In addition, I would have not been a member of such a prestigious group of international and governmental collaborators. In my first meeting with Fred, Fred asked me; “What do you know about lake sediment cores?” I replied; “All I know is that they are round.” Getting your first question wrong (sediment cores are cylindrical) does not leave a particularly good first impression; however, Fred remained confident in my abilities then, as much as he does now. I can say with confidence, that without Fred I would not have progressed to be the scholar I am today. Fred, thank you for all that you have provided me (skills, life lessons and countless delicious ‘feedings’). I am extremely honoured to have you as a supervisor –I am also grateful to call you my friend. I also thank Allan Crowe (Canada Centre for Inland Waters, Environment Canada) for facilitating core sampling, and the captain and crew of the Canadian Coast Guard Ship Limnos for core collection –ultimately the foundation for my Ph.D. project. Also at Canada Centre for Inland Waters, I thank Christina Jaskot, Brian Trapp and Ian Droppo for allowing me to obtain grain-size measurements in their laboratory. I sincerely thank Francine McCarthy (Brock University) for welcoming me into her lab and teaching me the skills to extract pollen from lake sediments. In addition, I thank Francine for allowing me to attend her wonderful course on palynology. I am grateful to John King and staff (University of Rhode Island, Graduate School of Oceanography) for providing sediment core images and the University of Arizona (AMS laboratory) for radiocarbon dates. Katrina Moser and Guy Plint (Ph.D. committee members) have also been a great help at various stages of project design and certainly advanced the project, thank you. I also thank the examination committee (Dan Shrubsole, Elizabeth Webb, Patricia Corcoran and Mike vi Lewis) for their thoughtful revisions and skillful questions during my defense. All of you have greatly advanced this work. Much of the analytical work would not be possible without the assistance of the staff of the Laboratory for Stable Isotope Science (The University of Western Ontario). I appreciate the time and patience offered by Kim Law, Grace Yau, and Li Huang. All of you have greatly advanced my technical skills in the field of stable isotope mass spectrometry and I thank you for that. I would also like to thank my laboratory and university colleagues that have provided helpful insight toward project design and assistance on experiments: Rebecca Macdonald, Ayumi Hyodo, Sam Russel, Duane Petts, Jessica Metcalfe, Beth Hundey, Natasha Bumstead, Nicolle Bellissimo, Christine Cizkowski, Nadine Wakabayashi, Paul Szpak, Scott Colborne, Farnoush Tahmasebi, Laura Sanchez and Nelson Cho. A special ‘thank you’ is needed for; (i) Avner Ayalon (Geological Survey of Israel) for enhancing my critical thinking skills in the field of isotope science, (ii) Mike Lewis (Geological Survey of Canada), ‘the godfather’ of Great Lakes research, for the many delightful and constructive talks about limnology in general and (iii) Nadia Dildar for coaching me through the process of lipid extraction and n-alkane measurements. The project would not be possible without funding. Operating funds were provided by a Natural Sciences and Engineering Research Council of Canada Discovery Grant (FJL) and an Ontario Graduate Scholarship (RH). Infrastructure support was provided by the Canada Foundation for Innovation and the Ontario Research Fund (FJL). The research was also made possible in part through additional research time provided through the Canada Research Chairs program. I also wish to express my gratitude toward the donors and organizations of the many scholarships I obtained; Robert and Ruth Lumsden Award, Graduate Thesis Research Award, Robert Hodder Travel Bursary, Kenneth N. Weaver Student Travel Award (Geological Society of America, North-eastern section), Geological Society of America Student Travel Award (North-central section), and the International Association for Great Lakes Research-Ontario Ministry of Natural Resources Student Travel Award. I thank the many friends I have. All of you have contributed to my success in one way or another, thank you for keeping me level-headed. Furthermore, I appreciated all the fun we vii have had together, especially the RRBD faithful (a short list of friends in no particular order): Carter Hutton, Billy Boquist, Mike and Kelly Sellan, Chris Unick, Adam Fron, Justin Everett, Troy Prezio, Brent Irwin, Steve Hosegood, Kevin Britton, Ryan Baird, Jeff Coull, Kory McEwan, Derrick Hosanna, Adam and Michelle Nemeth, Adam Fabiano, Brad and Nicole Yeo, Mark Davis, Peter