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Upper Jurassic-Lower Cretaceous Palynostratigraphy of the Aklavik Range, Northwest Territories, Arctic Canada

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Upper Jurassic-Lower Cretaceous Palynostratigraphy of the Aklavik Range, Northwest Territories, Arctic Canada University of Calgary PRISM: University of Calgary's Digital Repository Graduate Studies The Vault: Electronic Theses and Dissertations 2019-04-26 Upper Jurassic-Lower Cretaceous palynostratigraphy of the Aklavik Range, Northwest Territories, Arctic Canada Nguyen, Anne Van Nguyen, A. V. (2019). Upper Jurassic-Lower Cretaceous palynostratigraphy of the Aklavik Range, Northwest Territories, Arctic Canada (Unpublished master's thesis). University of Calgary, Calgary, AB. http://hdl.handle.net/1880/110242 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 Upper Jurassic-Lower Cretaceous palynostratigraphy of the Aklavik Range, Northwest Territories, Arctic Canada by Anne Van Nguyen A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE GRADUATE PROGRAM IN GEOLOGY AND GEOPHYSICS CALGARY, ALBERTA APRIL, 2019 © Anne Van Nguyen 2019 i ABSTRACT Quantitative palynostratigraphy of Lower Cretaceous rocks from the Aklavik Range, Northwest Territories, is used to provide insight into paleoenvironmental conditions in the Boreal Realm during the Jurassic-Cretaceous transition. Paleoenvironmental reconstruction of this time interval is based on palynoassemblages preserved in the Husky Formation (upper Tithonian – lower Berriasian). Relative abundance of ecologically important spore and pollen taxa such as Cupressaceae-Taxaceae and Classopollis classoides pollen reveal increasing humid conditions with a seasonally arid phase during the early Berriasian. Dinoflagellate cyst assemblages preserved in the purported Martin Creek Formation (lower Berriasian) include potential biostratigraphically significant species Oligosphaeridium cf. tenuiprocessum. A revised late Albian age is proposed for the succession, which may be stratigraphically attributed to the Arctic Red Formation. High relative abundance and diversity of fern spores indicate that high moisture conditions prevailed. Trends in the relative abundance of gymnosperm pollen suggest a transition from cool to warm temperatures during this time period. ii ACKNOWLEDGMENTS I would first and foremost like to extend my appreciation to my research supervisor, Dr. Jennifer Galloway, who has been a constant source of support and encouragement. Thank you for being such an exemplary role model, for encouraging me to step out of my comfort zone and become a better scientist. Without you, I would have never been able to experience so many incredible things during my graduate studies. I would also like to thank my co-supervisor, Dr. Benoit Beauchamp, who I hold in great esteem, for his support and guidance, fun anecdotes and overall positive attitude. I am also grateful to the many people at the Geological Survey of Canada, particularly Dr. Thomas Hadlari for helping me collect samples on the steeper slopes I was wary about climbing; Dr. Larry Lane for being so patient in explaining the geology and logistics of the study area; Dr. Terry Poulton for his advice on the biostratigraphy, and who was so open and willing to help with this thesis; Dr. Rob Fensome for teaching me about dinoflagellate cysts and patiently helping with species identification when I struggled with them; Dr. Manuel Bringué who helped with one of my figures; and Leanne Tingley who processed my samples despite the long period of construction at the GSC. I would also like to thank Drs. Alex Dutchak and Charles Henderson for agreeing to be a part of my review committee and for providing useful feedback. Thank you as well to my colleagues from the Arctic Geoscience Laboratory at the University for making the windowless lab room seem less dreary, and to all the professors and fellow graduate students with whom I worked as a teaching assistant, who showed me how fun teaching could be. iii DEDICATION For My beloved family and Connie, Emmée, and Eli – proof that mind melds can work long-distance iv TABLE OF CONTENTS ABSTRACT .................................................................................................................................... ii ACKNOWLEDGMENTS ............................................................................................................. iii DEDICATION ............................................................................................................................... iv LIST OF TABLES ....................................................................................................................... viii LIST OF FIGURES ....................................................................................................................... ix LIST OF PLATES .......................................................................................................................... x CHAPTER 1: INTRODUCTION ................................................................................................... 1 History of the Jurassic and Cretaceous Periods .......................................................................... 1 Defining the Jurassic-Cretaceous boundary ................................................................................ 2 Nomenclature and Placement of the J/K boundary ..................................................................... 8 The Boreal Realm of Canada ...................................................................................................... 9 Thesis Structure and Role of Student ........................................................................................ 18 References ................................................................................................................................. 21 CHAPTER 2: PALYNOSTRATIGRAPHY OF THE JURASSIC-CRETACEOUS TRANSITION IN THE NORTHERN RICHARDSON MOUNTAINS OF THE NORTHWEST TERRITORIES, ARCTIC CANADA .......................................................................................... 29 ABSTRACT .............................................................................................................................. 29 INTRODUCTION ..................................................................................................................... 30 GEOLOGIC SETTING AND STUDY AREA ......................................................................... 34 Beaufort-Mackenzie Region .................................................................................................. 37 Husky Formation ................................................................................................................... 42 Thermal Maturity ............................................................................................................... 46 Ammonite and Buchia Biostratigraphy in Arctic Canada ..................................................... 47 Previous Palynological Studies on the Jurassic-Cretaceous Boundary in Arctic Canada ..... 50 METHODS ................................................................................................................................ 55 Palynology ............................................................................................................................. 55 Multivariate Statistical Techniques ....................................................................................... 58 RESULTS .................................................................................................................................. 60 Spores and Pollen .................................................................................................................. 60 Dinoflagellate Cysts .............................................................................................................. 61 Multivariate Statistical Analyses: Q- and R-mode Cluster Analysis, CONISS .................... 67 Detrended Correspondence Analysis (DCA) ........................................................................ 73 v DISCUSSION ........................................................................................................................... 76 Biostratigraphy ...................................................................................................................... 76 Dinoflagellate Cysts ........................................................................................................... 76 Spores and Pollen .............................................................................................................. 81 Paleoecology .......................................................................................................................... 85 Bryophytes and Lycophytes ................................................................................................ 85 Ferns .................................................................................................................................. 86 Conifers .............................................................................................................................. 87 Cycads, Ginkgos, and Gnetophytes ................................................................................... 90 Paleoenvironment .................................................................................................................
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