Western University Scholarship@Western Electronic Thesis and Dissertation Repository 8-26-2015 12:00 AM Investigating potential climatic cycles in glacially-influenced rhythmites of the upper Gowganda Formation using geochemical, sedimentological and spectral analyses Timothy S. Howe The University of Western Ontario Supervisor Dr. Patricia Corcoran The University of Western Ontario Co-Supervisor Fred Longstaffe The University of Western Ontario Co-Supervisor Elizabeth Webb The University of Western Ontario Graduate Program in Geology A thesis submitted in partial fulfillment of the equirr ements for the degree in Master of Science © Timothy S. Howe 2015 Follow this and additional works at: https://ir.lib.uwo.ca/etd Part of the Geology Commons Recommended Citation Howe, Timothy S., "Investigating potential climatic cycles in glacially-influenced rhythmites of the upper Gowganda Formation using geochemical, sedimentological and spectral analyses" (2015). Electronic Thesis and Dissertation Repository. 3264. https://ir.lib.uwo.ca/etd/3264 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]. INVESTIGATING POTENTIAL CLIMATIC CYCLES IN GLACIALLY- INFLUENCED RHYTHMITES OF THE UPPER GOWGANDA FORMATION USING GEOCHEMICAL, SEDIMENTOLOGICAL AND SPECTRAL ANALYSES by Timothy Scott Howe Graduate Program in Geology A thesis submitted in partial fulfillment of the requirements for the degree of Master of Geology The School of Graduate and Postdoctoral Studies The University of Western Ontario London, Ontario, Canada © Timothy S. Howe, 2015 Abstract The upper Gowganda Formation of the Huronian Supergroup contains glacially-induced, varve-like rhythmites composed of turbiditic micro-laminae that potentially preserve a detailed record of climatic conditions during the Paleoproterozoic Era. A sedimentological analysis of upper Gowganda Formation deposits enabled identification of eight lithofacies comprising a glaciogenic depositional environment: 1) diamictite, 2) contorted argillite, 3) interlaminated siltstone and sandstone, 4) interbedded siltstone and claystone, 5) sandstone, 6) siltstone, 7) interbedded coarse-grained and fine-grained siltstone, and 8) wavy argillite. Major, trace, and rare earth element analyses indicate that the rhythmites have undergone limited recycling and chemical alteration. Whole-rock δ18O values are consistent with an Archean gneiss provenance and support that chemical weathering and diagenesis were insignificant. Spectral analysis of four rhythmic couplet thickness records using the MTM Toolkit of Mann and Lees (1996) supports the hypothesis of annual deposition for the rhythmites. Keywords Paleoproterozoic, Huronian, Gowganda, glaciation, rhythmites, varves, micro-laminae, MTM Toolkit, red noise model ii Acknowledgments Without the assistance of many people this thesis wouldn’t have been possible. First and foremost I’d like to thank my supervisor, Dr. Patricia Corcoran, and co-supervisors Dr. Fred Longstaffe and Dr. Elizabeth Webb, for giving me the opportunity to work on such an interesting and challenging project, and for providing guidance and support along the way. Capable field assistance was provided by Mansour Al-Hashim, Alex Hockin and Bethany Dean. Anthony Pace provided access to the core logged in this thesis. Linux computer access to operate the spectral analysis program was provided by Dr. Kristy Tiampo. Assistance with the spectral analysis chapter was provided by Dr. Gerhard Pratt. Dr. Gary Hughes kindly provided me with his data so that I could compare his data with my data using the same software. Dr. Guy Plint helped me by suggesting that I reduce my project to a more manageable size, and along with Omar Al-Mufti, encouraged me to take a closer look at sedimentological depositional processes. Ryan Hladyniuk assisted with technical and administrative issues. And finally, I’d like to acknowledge all of the faculty, students, and administrative staff that make up the Department of Earth Sciences here at Western: I’ve never worked with such a consistently agreeable group of people in my life, and I can honestly say that it was always a pleasure to “show up to work”. Warmest thanks to everyone for that. iii Table of Contents Abstract ............................................................................................................................... ii Acknowledgments.............................................................................................................. iii Table of Contents ............................................................................................................... iv List of Tables .................................................................................................................... vii List of Figures .................................................................................................................. viii List of Appendices ........................................................................................................... xiii 1 Introduction .................................................................................................................... 1 1.1 Varves ..................................................................................................................... 1 1.1.1 Varves in Glaciofluvial Lakes .................................................................... 2 1.1.2 Thermal Stratification in Glaciofluvial Lakes ............................................ 2 1.1.3 Thermal Stratification and Varves .............................................................. 3 1.1.4 Non-glacial Varves ..................................................................................... 4 1.2 Varves in Precambrian Settings .............................................................................. 4 1.3 Tidal Rhythmites ..................................................................................................... 5 1.4 Tidal Rhythmites in Precambrian Settings ............................................................. 7 1.5 Turbidites ................................................................................................................ 8 1.6 Glacially-influenced Turbidites in Precambrian Settings ....................................... 9 2 Geological Setting ........................................................................................................ 11 2.1 The Huronian Supergroup..................................................................................... 11 2.1.1 Elliot Lake Group ..................................................................................... 15 2.1.2 Hough Lake Group ................................................................................... 17 2.1.3 Quirke Lake Group ................................................................................... 19 2.1.4 Cobalt Group ............................................................................................. 20 2.1.5 Flack Lake Group ..................................................................................... 21 iv 2.2 Sudbury Igneous Complex .................................................................................... 23 2.3 Penokean Orogeny ................................................................................................ 23 2.4 Thesis Focus: Gowganda Formation .................................................................... 24 2.4.1 General Description .................................................................................. 24 2.4.2 Study Area ................................................................................................ 27 3 Sedimentology ............................................................................................................. 29 3.1 Lower Gowganda Formation ................................................................................ 29 3.2 Upper Gowganda Formation................................................................................. 30 3.2.1 Diamictite Lithofacies ............................................................................... 31 3.2.2 Contorted Argillite Lithofacies ................................................................. 32 3.2.3 Interlaminated Siltstone and Sandstone Lithofacies ................................. 36 3.2.4 Interbedded Siltstone and Claystone Lithofacies ...................................... 38 3.2.5 Sandstone Lithofacies ............................................................................... 48 3.2.6 Siltstone Lithofacies.................................................................................. 49 3.2.7 Interbedded Coarse-grained and Fine-grained Siltstone Lithofacies ........ 49 3.2.8 Wavy Argillite Lithofacies ....................................................................... 52 3.3 Depositional Model ............................................................................................... 53 3.4 Sedimentology Summary ...................................................................................... 56 4 Geochemistry ............................................................................................................... 58 4.1 Sample Preparation ............................................................................................... 58 4.2 Major,