Stratigraphy, Sedimentology, and Diagenesis of Ordovician Outliers, Northern Ottawa–Bonnechere Graben, Central Ontario by He Kang A thesis submitted to the Faculty of Graduate and Postdoctoral Affairs in partial fulfillment of the requirements for the degree of Master of Science in Earth Sciences Carleton University Ottawa, Ontario © 2017, He Kang Abstract Several Ordovician outliers along or near the northern Ottawa–Bonnechere graben are bounded by Precambrian rocks of the Canadian Shield. Correlation of outlier stratigraphy reveals that these remnant bodies form part of a once expansive Late Ordovician phase of the St. Lawrence Platform extending into the craton interior from the Laurentian margin. Integrating litho-, bio-, and chemostratigraphic data sets, four outliers (Deux Rivières, Brent Crater, Cedar Lake, and Manitou Islands) preserve Turinian strata, whereas a fifth (Owen Quarry outlier) illustrates how local downfaulting has preserved lower Chatfieldian strata. Each outlier documents a unique depositional succession but, in common, record shallow-water depositional environments during net transgression. Local diagenetic records reveal the roles of surface marine, shallow-burial, and deep-burial alteration of limestone. Several dolomite types are present: fabric-selective, pervasive replacement, and local fracture/paleovoid-fill. Isotope (C, O, Sr) signatures identify interaction of dolomitizing fluids with a 87Sr-enriched reservoir, and very negative δ18O values of dolomite suggest either elevated temperature or meteoric influence. Dolomite shows basement-related, stratabound, and fault/fracture-related spatial distributions. Early-stage dolomitization may be related to Mg derived from marine or meteoric waters whereas late-stage dolomitization, including hydrothermal saddle dolomite, likely involves brines that migrated along Paleozoic-Precambrian boundary, then refocused along vertical faults and fractures. In general, this study demonstrates stratigraphic and sedimentary connectivity in the Laurentia craton interior during the early Late Ordovician, and dolomitization that may be related to local and regional fluid migration. ii Acknowledgements First and foremost, I’d like to thank my thesis supervisor, George R. Dix for giving me the opportunity to work on this great project, and all the support and guidance through the completion of the thesis. For staffs of Carleton University, I’d like to thank Tim Mount for making thin-sections, Peter Jones for conducting microprobe analysis, Shuangquan Zhang for supervision of strontium isotope analysis, and Jianqun Wang for SEM analysis. Quarry owner and Ontario Parks are thanked for allowance of doing field work and field help from the latter. GSC-Ottawa is thanked for access of logging Brent Crater core and XRD analysis of clay samples. Queen’s Facility for Isotope Research (Queen’s University) and G.G. Hatch Stable Isotope Laboratory (University of Ottawa) contributed to carbon and oxygen isotope analysis. Sandy McCracken (GSC-Calgary) is thanked for processing and identifying conodont fauna. Yuefeng Shen (Laval University) helped with identification of cyanobacteria and algae. I also want to thank my committee members André Desrochers and Claudia Schrö der-Adams for their time reviewing my thesis and the comments that improved this thesis. I’d like to thank my office mates Nkechi Oruche and Wilder Greenman for all the help and discussions. Faculty members, staffs, and fellow graduate students at the Department of Earth Sciences, Carleton University are thanked for making my stay in the department enjoyable. Thanks to my friends for their accompany during my time in Ottawa. Finally, I want to thank my family members in China who have been consistent support during my stay in Canada, with special thanks to my father Yili Kang who introduced me to the field of geology. iii Table of Contents Abstract .............................................................................................................................. ii Acknowledgements .......................................................................................................... iii Table of Contents ............................................................................................................. iv List of Tables ................................................................................................................... vii List of Figures ................................................................................................................. viii List of Appendices ............................................................................................................ xi Chapter 1 Introduction..................................................................................................... 1 1.1 Paleozoic outliers, Ontario ........................................................................................ 1 1.2 Statement of research intent ...................................................................................... 4 1.3 Geological setting ...................................................................................................... 5 1.3.1 St. Lawrence Platform ........................................................................................ 5 1.3.2 Ottawa Embayment ............................................................................................ 8 1.3.3 Paleogeography and oceanography .................................................................... 9 1.4 Methodology ........................................................................................................... 11 1.4.1 Field methods ................................................................................................... 11 1.4.2 Laboratory methods .......................................................................................... 12 Chapter 2 Deux Rivières Outlier ................................................................................... 15 2.1 Local and general geology ...................................................................................... 15 2.2 Lithostratigraphy and facies .................................................................................... 15 2.3 Biostratigraphic indicators and age of outlier ......................................................... 32 2.4 Diagenesis ............................................................................................................... 36 2.4.1 Introduction ...................................................................................................... 36 2.4.2 Petrography ....................................................................................................... 37 2.4.3 Geochemistry .................................................................................................... 47 2.4.4 Discussion ......................................................................................................... 54 Chapter 3 Brent Crater .................................................................................................. 61 3.1 Introduction ............................................................................................................. 61 3.2 Lithostratigraphy and facies .................................................................................... 63 3.3 Biostratigraphic indicators and age of sedimentary fill .......................................... 82 3.4 Diagenesis ............................................................................................................... 83 3.4.1 Limestone ......................................................................................................... 85 iv 3.4.2 Dolostone .......................................................................................................... 85 Chapter 4 Cedar Lake Outlier....................................................................................... 87 4.1 Introduction ............................................................................................................. 87 4.2 Lithostratigraphy and facies .................................................................................... 87 4.2.1 Locality A ......................................................................................................... 87 4.2.2 Locality B ......................................................................................................... 94 4.2.3 Summary of depositional environments ........................................................... 96 4.3 Diagenesis ............................................................................................................... 96 4.3.1 Petrography ....................................................................................................... 96 4.3.2 Geochemistry .................................................................................................... 97 Chapter 5 Manitou Islands ............................................................................................ 99 5.1 Local and general geology ...................................................................................... 99 5.2 Lithostratigraphy and facies .................................................................................... 99 5.2.1 Great Manitou Island ........................................................................................ 99 5.2.2 Little Manitou Island .....................................................................................