Genesis of Carbonate Lakes on Perennial Siliciclastic Floodplains A thesis presented to the faculty of the College of Arts and Sciences of Ohio University In partial fulfillment of the requirements for the degree Master of Science Jessie J. Truchan June 2009 2 This thesis titled Genesis of Carbonate Lakes on Perennial Siliciclastic Floodplains by JESSIE J. TRUCHAN has been approved for the Department of Geological Sciences and the College of Arts and Sciences by Elizabeth H. Gierlowski-Kordesch Associate Professor of Geological Sciences Benjamin M. Ogles Dean, College of Arts and Sciences 3 ABSTRACT TRUCHAN, JESSIE J., M.S., June 2009, Geological Sciences Genesis of Carbonate Lakes on Perennial Siliciclastic Floodplains (112 pp.) Director of Thesis: Elizabeth H. Gierlowski-Kordesch Carbonate lake deposits interbedded with coal seams exist in perennial fluvial floodplain deposits during the Phanerozoic. Such lakes require that a protected water body must contemporaneously exist with a minimum of siliciclastic input. Meandering and braided river systems do not have areas shielded from siliciclastic bedload during floods, so that lacustrine carbonate or peat accumulation over time in these systems is interrupted. However, anastomosing river systems have flood basin areas surrounded by relatively high levees that protect those basins, allowing them to receive mostly suspended and dissolved load during most floods. This protection from siliciclastic input favors enhancement of carbonate precipitation. The water table must remain high to preserve peat for coal formation. This hydraulic control on carbonate and coal sedimentation in a fluvial system is dependent on flooding and groundwater characteristics. The other important control on carbonate and coal sedimentation is provenance. Carbonate accumulation in continental settings is dependent on the influx of ions from the weathered drainage area; sedimentary material, whether bedload, suspended load, or dissolved load, must come from the basinal source area. Bedrock with calcium-rich rocks can contribute sufficient quantities of dissolved to suspended load to allow for bio-mediated precipitation in protected carbonate ponds and lakes in association with plants. 4 In order to test this hypothesis that indeed carbonate sedimentation on perennial siliciclastic floodplains can primarily occur in anastomosing river environments, a database of over 200 examples mostly of perennial anastomosing and meandering river systems was compiled. Information regarding the fluvial parameters and facies characteristics of each Phanerozoic river deposit, the tectonics of its region, as well as the provenance was used to recognize carbonate sedimentation patterns through time and space. Difficulties in collecting data on single fluvial systems versus data averaged across successions containing multiple fluvial systems reduced the size of the dataset. Overall, 56 anastomosing river deposits were found to have carbonate floodplain lakes and a carbonate provenance. This means that 46% of all definitively anastomosing river deposits accumulated flood basin carbonates and 100% of these river deposits had a carbonate provenance. 66 anastomosing river systems (54%) did not have carbonates in their provenance nor in their flood basins, and no anastomosing systems had a carbonate provenance without carbonate deposits on their floodplains. No meandering river systems (8) had carbonate deposits, despite the fact that four of the meandering entries had carbonates in their source area. This research contributes sedimentologic criteria helpful to coal exploration and the refinement of fluvial depositional system models. Approved: _____________________________________________________________ Elizabeth H. Gierlowski-Kordesch Associate Professor of Geological Sciences 5 ACKNOWLEDGMENTS I would like to express my genuine gratitude and sincere thanks to Dr. Elizabeth Gierlowski-Kordesch, my advisor, for her support, guidance, and especially for her laughter. She really helped me out and I feel like a better person from knowing her. I am grateful to Dr. Joseph Shields, Karen Mammone, and Dr. Michael Root for their inspiration and teachings. I am truly grateful to my committee members, Dr. Gregory Nadon and Dr. David L. Kidder for their questions and direction. I also wish to thank the Department of Geological Sciences,ExxonMobil for financial support, my friends, my sister Jolene Truchan, William Holland, my grandparents and especially my parents, Wayne and Brenda Truchan, for always being there for me. 6 TABLE OF CONTENTS Page Abstract ............................................................................................................................... 3 Acknowledgments............................................................................................................... 5 List of Tables ...................................................................................................................... 8 List of Figures ..................................................................................................................... 9 Chapter 1: River Systems and floodplains ........................................................................ 10 Meandering Rivers: Definition and Facies Model ........................................................ 14 Anastomosing Rivers: Definition and Facies Model .................................................... 20 Floodplains .................................................................................................................... 25 Chapter 2: Carbonate Lakes/Floodplain Lakes ................................................................. 28 Previous Models ........................................................................................................... 28 Isolation ..................................................................................................................... 28 Groundwater Springs ................................................................................................ 29 Dry Climate ............................................................................................................... 32 Metamorphic Provenance ......................................................................................... 32 Carbonate Lake Formation on Siliciclastic Floodplains ............................................... 33 Provenance .................................................................................................................... 36 Carbonates Interbedded with Coal ................................................................................ 37 Chapter 3: Database .......................................................................................................... 38 Hypothesis .................................................................................................................... 38 Methodology ................................................................................................................. 38 7 Results ........................................................................................................................... 43 Discussion ..................................................................................................................... 47 Conclusions ................................................................................................................... 50 Future Work and Significance ...................................................................................... 52 References ......................................................................................................................... 53 Appendix A: Database of Ancient River Systems ............................................................ 67 Appendix B: Anastomosing Entries from Appendix A .................................................... 81 Appendix C: Meandering Entries from Appendix A ........................................................ 87 Appendix D: Entries with No CHANNEL Width/Thickness Ratios ................................ 88 Appendix E: References for Appendix D ......................................................................... 90 Appendix F: References for Appendix A, B, and C ......................................................... 93 Appendix G: Quaternary References for Table 2 in Chapter 3 ...................................... 111 8 LIST OF TABLES Page Table 1. List of Abbreviations used in the Database ........................................................ 39 Table 2. List of Quaternary River Systems with Anastomosing Reaches ......................... 42 Table 3: Results ................................................................................................................. 46 Table 4. River Systems ...................................................................................................... 67 Table 5. Anastomosing Entries ......................................................................................... 81 Table 6. Meandering Entries from Appendix A ................................................................ 87 Table 7. Entries with No Width/Thickness Ratios ............................................................. 88 9 LIST OF FIGURES Page Figure 1. A block diagram from Walker and Cant (1984) describing important morphologic features of a meandering river system. ........................................................ 14 Figure 2. Generalized stratigraphic column and formation