Deposition and Diagenesis of the Early Permian Lower Parmeener Supergroup Limestones, Tasmania

Deposition and Diagenesis of the Early Permian Lower Parmeener Supergroup Limestones, Tasmania Becky Rogala A thesis submitted to the Department of Geological Sciences and Geological Engineering in conformity with the requirements for the degree of Doctor of Philosophy Queen’s University Kingston, Ontario, Canada April, 2008 Copyright © Becky Rogala, 2008 ASTRACT The Lower Parmeener Supergroup consists of 500 to 900 metres of marine and terrigenous sedimentary rocks, deposited in the high-latitude Tasmania Basin during the late Carboniferous to middle Permian, at the end of the late Paleozoic ice age. Two bioclastic carbonate units, the Darlington and Berriedale limestones, are of particular interest due to their formation in this polar, cold-water environment. Both limestones contain ice-rafted debris scattered throughout, signifying numerous icebergs, and are under- and over-lain by glendonitic siltstone indicating near-freezing seawater. Despite the unusual environment, seawater in the Permian Tasmania Basin was, with the exception of an anomalously high δ13C value, isotopically and chemically similar to modern seawater. These limestones consist of a high-abundance, low-diversity heterozoan assemblage, dominated by large, robust brachiopods, bryozoans, and Eurydesma bivalves. Sponge spicules and crinoids are locally important constituents. The carbonates are interpreted to have been deposited in mid-shelf environments during sea-level highstands, where the faunal communities were beyond the depths of grounding icebergs, and sufficiently outboard from terrigenous sediment influx and brackish water. Growth and preservation of biogenic carbonates were promoted by up-welling of nutrient-rich water, which sustained high levels of primary productivity in the water column and phosphate concentrations in the sediment. ii Lower Parmeener Supergroup carbonates were exposed to a complex series of diagenetic processes, commencing on the seafloor and continuing during rapid burial. Limestone composition was further modified by diagenetic fluids associated with the intrusion of Mesozoic igneous rocks. Alteration in the marine paleoenvironment was both destructive and constructive; although dissolution took place there was also coeval precipitation of fibrous calcite cement, phosphate, and glauconite. These processes are interpreted to have been promoted by mixing of marine waters and enabled by microbial degradation of organic matter. In contrast, meteoric diagenesis was insignificant, being confined to minor dissolution and localized cementation, although mechanical compaction was ubiquitous. Chemical compaction was instigated at burial to depths of approximately 150 m, and promoted extensive precipitation of ferroan calcite. Diagenesis may well have ended here, except for the subsequent intrusion of massive Mesozoic diabases and associated injection of silicifying fluids into the limestones. Finally, fractures associated with Cretaceous uplift were filled with late-stage non-ferroan calcite cement. iii STATEMENT OF CO-AUTHORSHIP The following manuscripts are my own work, but owe much to the intellectual and scientific guidance, and precise editing, of Dr. Noel P. James, who is co-author of each manuscript and supervisor of this thesis research. Co- authors Dr. Catherine M. Reid (manuscript 1), Clive R. Calver (manuscript 2), and T. Kurtis Kyser (manuscript 3) provided invaluable scientific advice and discussion that led to the improvement of this thesis. iv ACKNOWLEDGEMENTS I would like to express my gratitude to Dr. Noel James for his guidance through the pitfalls of graduate studies. His boundless enthusiasm for teaching and for science is infectious. Under his tutelage I learned not only about the intricacies of carbonate sedimentology and diagenetic processes, but also about the qualities that make a great teacher and supervisor. I am also thankful for the incredible opportunities I have been given: field-trips to Bermuda, New York, and Quebec, field work in Australia, and of course the chance to work on my presentation techniques for GSA. I would also like to thank Dr. Kurt Kyser for his patient explanations while I developed my geochemical intuition, and for advising on Lower Parmeener Supergroup geochemistry. I am also appreciative of the assistance provided by Kerry Klassen with preparing samples and running stable isotope analyses, and to Dr. Don Chipley and Bill MacFarlane for directing the preparation of samples and running elemental geochemistry analyses. Catherine Reid and Clive Calver were instrumental to the completion of this thesis. Thank you to both of them for introducing me to the Lower Parmeener Supergroup. Catherine was particularly helpful in keeping my stratigraphic nomenclature straight, as well as providing insightful advice regarding the depositional environments and stratigraphic relationships. Clive’s knowledge of outcrops in the Tasmania Basin and keen observations of grain and diagenetic relationships were invaluable. v I would like to acknowledge two of my fellow graduate students who were always available for impromptu thesis discussions. A big thank you to John Rivers for a willingness to chat about all things carbonate, particularly anything related to geochemistry. It has been interesting sharing an office with John during these last four years between ducking paper missiles, playing the “Price is Right”, listening to his plans to be a truck driver instead, and enduring seemingly endless seasons of NFL – go Eagles. Thanks for keeping it fun. I’m also grateful to Mike Johnson for always being available for discussions on sequence stratigraphy. I’m sure he explained it to me a half dozen times before it sunk in – thanks for your patience. Of course my acknowledgements would not be complete without expressing my gratitude to Tom Hamilton, my husband and field assistant. This thesis would not have been possible without your expert fossil extraction skills and core-splitting abilities. Thank you for following me down to southern Ontario and Tasmania, for distracting me just enough to stay sane, and for the continual encouragement along the way. vi TABLE OF CONTENTS Abstract …………………………………….………………..………………….…. ii Statement of Co-Authorship …………………………….….……….………….… iv Acknowledgements ……………………………………..…………….……...…… v Table of Contents ……………………………………….………………………… vii List of Tables …………………………………….………………………………… viii List of Figures ……………………………………….………………..…………… viii Dedication ……………………………………………………………..…………… x CHAPTER 1: General Introduction ……………………………………...………. 1 CHAPTER 2: Deposition of polar carbonates during interglacial highstands on an Early Permian shelf, Tasmania (Journal of Sedimentary Research, v. 77, p. 587-606) Rogala, B., James, N.P., and Reid, C.M. ………………….……. 12 CHAPTER 3: Diagenesis of Early Permian high-latitude limestones, Lower Parmeener Supergroup, Tasmania (Sedimentology, in review) Rogala, B., James, N.P., and Calver, C.R. …………………...… 66 CHAPTER 4: Geochemistry of Permian brachiopods and eurydesmid bivalves from the Lower Parmeener Supergroup in Tasmania: implications for deducing paleoceanographic conditions from biogenic carbonates (Journal of Sedimentary Research, in review) Rogala, B., Kyser, T.K., and James, N.P. …………………….… 111 CHAPTER 5: General Summary and Extended Conclusions ……………...… 141 References ……………………………………..…………………………..……… 149 Appendix A: Core Logs ……………………………………………………….…... 182 vii LIST OF TABLES CHAPTER 1 Table1.1: Summary of Tasmanian, Australian, and Pangean Events …... 6 CHAPTER 2 Table 2.1: Summary of lithofacies in the Lower Parmeener Supergroup 24-25 CHAPTER 3 Table 3.1: Summary of calcite cement properties ………………………..… 80 CHAPTER 4 Table 4.1: Summary of diagenetic stages recorded in the petrography of limestones from the Permian Lower Parmeener Supergroup … 119 Table 4.2: Brachiopod isotopic and elemental geochemistry …………….. 123 Table 4.3: Eurydesmid isotopic and elemental geochemistry …………….. 125 LIST OF FIGURES CHAPTER 1 Figure 1.1: Reconstruction of Pangea ……………………………………....... 5 Figure 1.2: Reconstruction of Late Paleozoic ice extent ……………………. 8 CHAPTER 2 Figure 2.1: Location map ………………………………………………….....… 14 Figure 2.2: Stratigraphic relationships of units in the Lower Parmeener Supergroup ………………………………………………..…..…… 17 Figure 2.3: Lower Parmeener Supergroup nomenclature used in this study 18 Figure 2.4: Regional geology and distribution of drill holes ………………... 20 Figure 2.5: Extent of glaciation ………………………………………………... 21 Figure 2.6: Lower Parmeener Supergroup cross-section ………………….. 26 Figure 2.7: Siliciclastic-dominated lithofacies ……………………………...… 28 Figure 2.8: Carbonate lithofacies ……………………………………………... 35 Figure 2.9: Spiculitic limestone lithofacies …………………………………… 39 Figure 2.10: Plan and cross-section views of facies distribution — Asselian 41 viii Figure 2.11: Plan and cross-section views of facies distribution — Sakmarian 43 Figure 2.12: Plan and cross-section views of facies distribution — late Sakmarian/early Artinskian …………………………………..…… 45 Figure 2.13: Plan and cross-section views of facies distribution — Artinskian 47 Figure 2.14: Sequence stratigraphic section of the Lower Parmeener Supergroup ………………………………………………………… 49 CHAPTER 3: Figure 3.1: Reconstruction of eastern Pangea ……………………………… 69 Figure 3.2: Position of the Darlington and Berriedale limestones within the Lower Parmeener Supergroup stratigraphy ……………...… 70 Figure 3.3: Regional geology of Tasmania …………………………………... 73 Figure 3.4: Thin-section photomicrographs of representative facies

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