Refining the marine reservoir effect in the Northwest North Atlantic Thomas Neulieb Department of Geography McGill University Montreal, Quebec December, 2013 A thesis submitted to McGill University in partial fulfillment of the requirement of the degree of Masters of Science © Thomas Neulieb 2013 i Table of Contents Abstract ............................................................................................................................. vii Résumé ............................................................................................................................... ix Acknowledgements ............................................................................................................ xi Chapter 1: Background and Literature Review .................................................................. 1 The importance of dating in paleoclimatic research .................................................... 1 The basics of radiocarbon (14C) dating ........................................................................ 1 14C production and dilution ......................................................................................... 3 Radiocarbon dating and the Marine Reservoir Effect (MRE) ..................................... 5 The 8.2 ka Event, Preboreal Oscillation, the Younger Dryas, and the Marine Reservoir Effect ........................................................................................................... 7 Symbiosis in the foraminifera .................................................................................... 10 Effects of diagenetic processes on calcium carbonate carbon isotopes ..................... 14 Removing diagenetic products from carbonate shells ............................................... 18 Detecting alteration of original 14C concentration ..................................................... 18 Pollen dating .............................................................................................................. 19 Objectives ...................................................................................................................... 20 Chapter 2: Study Area and Methodology ......................................................................... 21 Study Area ..................................................................................................................... 21 Ocean sediment core descriptions ............................................................................. 21 Wetland core descriptions ......................................................................................... 24 Wetland deposits........................................................................................................ 24 Methods ......................................................................................................................... 25 Pollen extraction and analysis ................................................................................... 25 Calibration of 14C dates ............................................................................................. 26 Corrections specific to marine 14C dates ....................................................................... 27 Global mean and regional ΔR.................................................................................... 27 Sea ice corrections ..................................................................................................... 28 Date comparisons ...................................................................................................... 28 Chapter 3: Results ............................................................................................................. 30 Pollen 14C dates versus 137Cs and 210Pb dates ............................................................ 30 ii Macrofossils from James Bay buried wetland deposits ............................................. 31 Carbonate from ocean sediments ............................................................................... 32 Chapter 4: Discussion ....................................................................................................... 35 Pollen 14C dates versus 137Cs and 210Pb dates ............................................................ 35 Pollen 14C dates versus 14C-dated macrofossils from James Bay .............................. 36 Pollen 14C dates versus 14C-dated marine carbonates ................................................ 37 Evaluation of the MRE for the Eastern Canadian Margin ......................................... 40 Chapter 5: Summary, Conclusions, and Recommendations ............................................. 42 References ......................................................................................................................... 44 Appendix 1 ........................................................................................................................ 84 Concentrating and Extracting Pollen............................................................................. 84 Pollen Grain Extraction ................................................................................................. 86 iii List of Tables Table 1: 14C Pollen Dating and 210Pb/137Cs Dating Comparisons. ................................... 53 Table 2: 14C Pollen Dating and 14C Botanical Macrofossil Dating Comparison. ............. 54 Table 3: 14C Pollen Dating and 14C Marine Carbonate Dating Comparisons. .................. 55 Table 4: Percentage of reworked pollen grains. ................................................................ 57 iv List of Figures Figure 1: Location of cores used in this study. ................................................................. 58 Figure 2: Core stratigraphy for MD99-2225, Bay of Islands, Newfoundland .................. 59 Figure 3: Core stratigraphy for 2005033B-21PC , Inner Makkovik Bank. ...................... 60 Figure 4: Core stratigraphy for 2005033B-22PC, Inner Makkovik Bank. ....................... 61 Figure 5: Core stratigraphy for 2010023-11PC, Notre Dame Channel. ........................... 62 Figure 6: Core stratigraphy for 83033-07PC, NE Newfoundland Shelf ........................... 63 Figure 7: Core stratigraphy for 87033-19PC, Central NE Newfoundland Shelf. ............. 64 Figure 8: Radionuclide profiles for Malpeque Bay, PEI. .................................................. 65 Figure 9: Radionuclide profiles for Kouchibouguacis, NB .............................................. 66 Figure 10: 210Pb and 137Cs activity for the AMC core………………………………….................................................................................67 Figure 11: Lithostratigraphy and age vs. depth for core W25 and W55 (Eastern James Bay region) ………………………………………………………………………………68 Figure 12: Relationship between extended sea ice cover duration (months beyond the present day duration) and the aging effect in surface ocean waters.................................. 69 Figure 13: Examples of degredated pollen grains from select study area sediment cores. ........................................................................................................................................... 70 Figure 14: Calibrated 14C age comparison between pollen and marine carbonate in core 2005033B-22PC at a depth of 565-566 cm....................................................................... 71 Figure 15: Calibrated 14C age comparison between pollen and marine carbonate in core 2010023-11PC at a depth of 298-300 cm and the ocean sample at 300-302 cm .............. 72 v Figure 16: Total carbonate percentage in cores 87033-19PC and 83033-07PC ............... 73 Figure 17: Palynomorph concentrations in core 87033-19P. ............................................ 74 Figure 18: Calibrated 14C age comparison between pollen and marine carbonate in core 87033-19PC at 874-877 cm depth (pollen) and 875-877 cm (marine carbonate) ............ 75 Figure 19: Calibrated 14C age comparison between pollen and marine carbonate in core MD99-2225 at 1440-1442 cm depth ................................................................................. 76 Figure 20: Calibrated 14C age comparison between pollen and marine carbonate in core 2005033B-21PC at 755-756 cm depth .............................................................................. 77 Figure 21: Calibrated 14C age comparison between pollen and marine carbonate in core Comparison 2005033B-21PC at 957 cm depth ................................................................ 78 Figure 22: Calibrated 14C age comparison between pollen and marine carbonate in core 2005033B-21PC at 1038 cm depth ................................................................................... 79 Figure 23: Calibrated 14C age comparison between pollen and marine carbonate in core 83033-07PC at 65-67 cm depth ........................................................................................ 80 Figure 24: Calibrated 14C age comparison between pollen and marine carbonate in core 83033-07PC at 217-218 cm depth .................................................................................... 81 Figure 25: Calibrated 14C age comparison between pollen and marine carbonate in core 87033-19PC at 503-504 cm depth (pollen) and 503-505 cm (marine carbonate) ............ 82 Figure 26: Calibrated 14C age comparison between pollen and marine carbonate in core 87033-19PC at 778-779 cm depth (pollen) and 775-780 cm (marine carbonate) ............ 83 vi Abstract This research examines