Mineraiogy, Lithostratigraphy and Geochemistry of North Lngebright Lake, Saskatchewan, Canada

Mineraiogy, Lithostratigraphy and Geochemistry of North lngebright Lake, Saskatchewan, Canada BY Yuqiang Shang A Thesis Submitted to the Faculty of Graduate Studies in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Department of Geological Sciences University of Manitoba Winnipeg, Manitoba (c) December, 2000 National Library Bibliothèque nationale 1+1 ,,,da du Canada Acquisitions and Acquisitions et Bibliographic Services seMces bibliographiques 395 Weliington Street 395. rue Wellington OttawaON KlAON4 Oîtawa ON KIA ON4 Canada Canada The author has granted a non- L'auteur a accordé une licence non exclusive licence allowing the exclusive permettant a la National Library of Canada to Bhliotheque nationale du Canada de reproduce, loan, distri'bute or sell reproduire, prêter, distribuer ou copies of this thesis in microform, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/nlm, de reproduction sur papier ou sur format électronique. 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THE UNIVERSITY OF MANITOBA FACULTY OF GRADUATE STUDIES ***** COPYRIGHT PERMISSION PAGE MineraIogy, Lithostratigraphy and Geochemistry of North Iigebright Lake, Saskatchewan, Canada Yuqiang Shang A ThesidPracticum submitted to the Facuity of Graduate Studies of The University of Manitoba in partial fuif?liment of the reqnirements of the degree of Doctor of Phüosophy YUQIANG SHANG O 2000 Permission has been granted to the Library of The University of Manitoba to lend or seii copies of this thesis/practicum, to the National Library of Canada to microfilm this thesidpracticum and to lend or seii copies of the Nm, and to Dissertations Abstracts International to publish an abstract of this thesidpracticum. The author reserves other publication rights, and neither this thesidpracticum nor extensive extracts ftom it may be printed or otherwise reproduced without the author's written permission. ABSTRACT North Ingebright Lake, containing Canada's thickest known Holocene terrestrial salt sequence, is a small (1.25 km2), hypersaline playa basin located in the Great Sand HiIls area of southwestern Saskatchewan. Because of its remarkably thick lacustrine sedimentary fill, the basin offers considerable potential for providing a high resolution record of past environmental changes in a region that has few other sources of Holocene paleoenvironmental information. Until recently, efforts to acquire cores of this thick sequence of well-indurated but very soluble salt have been unsuccessful using conventional coring techniques. However, exceptional sediment recovery was achieved using a compressed-air diamond drilling technique that permitted collection of continuous, large-diameter, undisturbed and chemically unaltered cores. The 10,000 year long lacustrine sequence recovered from the basin consists of well-indurated salt, with only minor dispersed mud and organic debris. Indeed, the section is remarkable in its lack of obvious bedding, colour variation or other visible sedimentary structures. The minera1 suite of these Holocene salts consists mainly of hydrated Na, Mg, Ca, and Mg+Na sulfates, carbonates, and chlorides. Minor amounts of nitrate evaporitic minerals also occur. This long uninterrupted sequence of soluble salts implies that the lake was characterized by high salinity throughout its Holocene history. However, variations in the mineralogy of the salts suggest that the basin experienced significant changes in brÏne composition. These evaporites, which allow a detailed reconstruction of specific ion activities and ratios in the brine through time, provide our evidence of the complexity of brine evolution in a closed-basin lacustrine environment in western Canada. TABLE OF CONTENTS Abstract Paae Chapter 1 -Introduction ...................................... 1 1.1 Overview ........................................ 1 1.2 General Characteristics of Saline Lakes ............... 2 1.3 Conditions of Lake Formation in the Canadian Prairies . 4 1.4 Economic Significance of Salt Lakes ................. 6 1.5 Previous Work on North Ingebright Lake .............. 8 1.6 Objective of Research .............................. 9 1.7 Acknowledgements ............................... 10 Chapter 2 -Regional Setting ................................. 11 2.1 Physiography .................................... 11 2.2 Summary of Late Deglaciation History of the Canadian Prairies ......................................... 12 2.3StudyArea ...................................... 15 2.3.1 Location .................................. 15 2.3.2 Climate .................................. 19 2.3.3 Regional Geology .......................... 22 2.3.4 Hydrology and Hydrologie Setting .............. 25 2.4 Modern Sedimentology of North lngebright lake ....... 29 Chapter 3 -Methodology .................................... 32 3.1 Core Acquisition ................................. 32 3.1.1 Drilling Site Selection ........................ 32 3.1.2 Drilling Techniques ......................... 32 3.1.3 Diamond Drilling ........................... 36 3.1.4 Coring ................................... 38 3.2 Laboratory Analyses .............................. 40 3.2.1 Organic Matter Content ...................... 42 3.2.2 Total Carbonate Content ..................... 42 3.2.3 Chronology ...............................44 3.2.4 Mineralogy ................................ 45 3.2.5 Geochemical Simulation ..................... 46 3.2.6 Statistical Methods ......................... 48 Chapter 4 -Lithostratigraphy of North Ingebright Lake ....... 49 4.1 General Description .............................. 49 4.2 General Stratigraphic Variation of Mineralogical Constituents .................................... 57 4.3 Lithostratigraphy ................................. 60 4.3.1 Unit 1 Basal Black Mud ...................... 60 4.3.2 Unit 2 Na-Sulfate Salt ....................... 69 4.3.3 Unit 3 Mg-Carbonate--Na-Sulfate Salt ........... 70 4.3.4 Unit 4 Ca-Sulfate--Na-Sulfate Salt .............. 73 4.3.5 Unit 5 Muddy Na-Sulfate Salt ................. 75 4.3.6 Unit 6 Na-Sulfate Salt ....................... 76 4.3.7 Unit 7 Muddy Mg-Calcite--Na-Sulfate Salt ........ 77 4.3.8 Unit 8 Dolomitic Na-Sulfate Salt ............... 78 4.4 Stratigraphic Correlation Within North lngebright Lake Basin .......................................... 80 Chapter 5 -Mineralogy of North lngebright Lake Core ........ 84 5.1 General Description .............................. 84 5.2 Origin of Mineralogical Constituents ................ 84 III Significance of Carbonate Mineralogy in North lngebright Lake .................................. 86 Soluble Evaporitic Mineralogy in North lngebright Lake . 89 Chapter 6 -Geochemistry of Sedimentation ................ 108 6.1 Introduction .................................... 108 6.2 Basis of Chemical Composition Reoconstruction ..... 109 6.3 Geochemical History of North lngebright lake ........ 113 6.3.1 Unit 2 Na-Sulfate Salt ...................... 116 6.3.2 Unit 3 Mg-Carbonate--Na-Sulfate Salt .......... 119 6.3.3 Unit 4 Ca-Sulfate--Na-Sulfate Salt ............. 123 6.3.4 Unit 5 Muddy Na-Sulfate Salt ................ 124 6.3.5 Unit 6 Na-Sulfate Salt ...................... 126 6.3.6 Unit 7 Muddy Mg-Calcite--Na-Sulfate Salt ....... 128 6.3.7 Unit 8 Dolornitic Na-Sulfate Salt .............. 129 6.4 Summary of Chemical Sedimentation ............... 131 Chapter 7 -North lngebright Lake: A Dynamic Closed-Basin Lake System .................................... 134 7.1 Introduction .................................... 134 7.2 Thermodynamic Activity of H2O and Salinity ......... 134 7.3 Water Activity. Relative Humidity. and Mineral Facies . 135 7.4 Hydrological balance and Mineral Precipitation ...... 139 7.4.1 Hydrological Balance ....................... 139 7.4.2 Numerical Simulation-Mineral Precipitation ...... 142 7.5 Hydrological Conditions of North Ingebright Lake .... 153 7.6 Noth lngebright Lake Relative to Other Holocene Lacustrine Records .............................. 154 Chapter 8 -Summary . 161 References Cited . 164 Appendix A Organic Matter and Carbonate Content Data 187 Appendix B Bulk Mineralogical Data from XRD . 201 Appendix C Detailed Evaporite Mineralogy from uPDSM 273 Appendix D Major Ion Ratios of Different Çtratigraphic Units . 347 Appendix E Core Descriptions . 371 Appendix F Statistical Analyses . 374 LlST OF FIGURES . VI LlST OF TABLES . ix Figure 1.1 Classification of saline lakes . 3 Figure 2.1 Sequence of proglacial lakes in Saskatchewan and adjacent areas .................................................. 14 Figure 2.2 Map showing the sediment thickness of North lngebright Lake in the northern Great Plains of western Canada . 16 Figure 2.3 Surface deposits of the Great Sand Hills region . 20 Figure 2.4 Mean water composition (rnilli-equivalentx) of North Ingebright Lake, inflowing springs, deep groundwater and shallow groundwater . 26 Figure 2.5 Trilinear diagrams of ionic composition (milli-equivalent%) of shallow groundwater in North Ingebright Lake region . 27 Figure 2.6 Trilinear diagrams of ionic composition (rnilli-equivalent%) of de,ep groundwater in North lngebright Lake region

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