Front Cover Supplied by LOC Title Page Supplied by LOC SALT LAKES OF THE NORTHERN GREAT PLAINS William M. Last Department of Geological Sciences University of Manitoba Winnipeg, Canada R3T 2N2 email: [email protected] and Lynn I. Kelley Saskatchewan Geological Survey Saskatchewan Energy and Mines Regina, Canada S4P 3V7 email: [email protected] Post-Conference Field Trip B2 May 30-31, 2002 SALT LAKES OF THE NORTHERN GREAT PLAINS Table of Contents 1. WELCOME & OBJECTIVES OF EXCURSION.......................................................................1 1.1 ACKNOWLEDGMENTS.............................................................................................2 2. ITINERARY & GENERAL ADVICE TO PARTICIPANTS.....................................................3 2.1 THURSDAY, MAY 30.................................................................................................3 2.2 FRIDAY, MAY 31........................................................................................................4 2.3 MISCELLANEOUS ADVICE......................................................................................4 3. INTRODUCTORY COMMENT: THE NORTHERN GREAT PLAINS...................................5 3.1 INTRODUCTION.........................................................................................................5 3.2 SCOPE & RATIONALE OF GEOLIMNOLOGY IN THE NORTHERN GREAT PLAINS...................................................................................................................5 3.3 SETTING & PHYSICAL BACKGROUND FOR GEOLIMNOLOGY ON THE NORTHERN GREAT PLAINS..............................................................................7 3.3.1 Geomorphology..............................................................................................7 3.3.2 Climate............................................................................................................8 3.3.3 Hydrology & Geology....................................................................................9 3.3.4 Fauna & Flora...............................................................................................11 4. HYDROCHEMISTRY OF THE SALT LAKES......................................................................11 4.1 INTRODUCTION.......................................................................................................11 4.2 SIXTY YEARS OF HYDROCHEMISTRY ..............................................................12 4.3 GROUNDWATER COMPOSITION..........................................................................13 4.4 WHAT DO WE KNOW ABOUT THE CHEMICAL COMPOSITION OF THESE SALT LAKES?......................................................................................................13 4.4.1 Salinity & Composition................................................................................13 4.4.2 Spatial Variation...........................................................................................16 4.4.3 A Statistical Approach: Insight into Water Composition Controlling Factors?......................................................................................................22 4.4.4 Temporal Variation.......................................................................................24 4.4.4.1 Short-term Variation......................................................................24 4.4.4.2 Long-term Temporal Variation......................................................25 4.4.5 Source of Salts..............................................................................................25 4.4.6 Summary of Water Chemistry Considerations.............................................26 5. THE MODERN LAKES............................................................................................................27 5.1 SIZE & SHAPE OF THE LAKES..............................................................................27 5.2 ORIGIN OF THE LAKE BASINS..............................................................................29 5.3 SEDIMENTS & SEDIMENTARY PROCESSES......................................................30 5.3.1 Sediment types..............................................................................................30 5.3.2 Detrital versus chemical sediments...............................................................32 6. THE SPECTRUM OF EVAPORITES IN THE SALT LAKES...............................................42 6.1 CRUSTS & HARDGROUNDS...................................................................................42 6.2 MASSIVE & BEDDED SALTS.................................................................................44 6.3 SPRING DEPOSITS....................................................................................................45 6.4 SUBSURFACE ACCUMULATIONS........................................................................46 6.5 PROCESS-PRODUCT CONTINUUM IN SALT LAKES.........................................48 7. NOTES ON MIRABOLITES....................................................................................................49 7.1 CARBONATE ACCRETIONARY GRAINS VERSUS MIRABOLITES.................49 7.2 THE MIRABOLITE GRAINS....................................................................................50 7.3 HOW & WHY DO THEY FORM...............................................................................50 8. ECONOMIC ASPECTS OF THE LAKES...............................................................................51 9. SALT LAKE PALEOLIMNOLOGY IN THE NORTHERN GREAT PLAINS......................54 9.1 INTRODUCTION.......................................................................................................54 9.2 MINING INDUSTRY ACTIVITY..............................................................................55 9.2.1 Metiskow Lake Example..............................................................................55 9.3 POST-DEPOSITIONAL CHANGES..........................................................................56 9.3.1 Mineral Diagenesis.......................................................................................56 9.3.2 Salt Dissolution & Karsting..........................................................................57 9.3.3 Mud Diapirism..............................................................................................58 9.4 SEDIMENTARY & GEOCHEMICAL PROCESSES & CONCEPTS......................58 9.4.1 Significance of Fine Grained Clastic Units..................................................58 9.4.2 Significance of Carbonate Mineralogy.........................................................59 9.4.3 Importance of Saline Mineral Metastability.................................................60 9.5 THE PALEOLIMNOLOGICAL FUTURE.................................................................60 9.5.1 Texture..........................................................................................................61 9.5.2 Quantitative Paleochemistry.........................................................................62 9.5.3 Isotopic Studies.............................................................................................64 9.5.4 Laminae & Other Bedding Features.............................................................65 9.5.5 Summary.......................................................................................................65 10. NOTES ON THE LAKES VISITED THURSDAY, MAY 30................................................67 10.1 PORTER-BURKE LAKES.......................................................................................67 10.2 PATIENCE LAKE.....................................................................................................68 10.3 MUSKIKI LAKE.......................................................................................................69 10.4 DANA & BERRY LAKES........................................................................................71 10.5 WALDSEA & DEADMOOSE LAKES....................................................................72 10.5.1 Why Are We Here?.....................................................................................72 10.5.2 The Modern Lakes......................................................................................73 10.5.2.1 Setting..........................................................................................73 10.5.2.2 Limnology & Hydrogeology........................................................73 10.5.2.3 Modern Sedimentology................................................................76 10.5.3 Stratigraphy of the Lacustrine Sediments...................................................76 10.5.3.1 Aragonite Laminae Petrography..................................................78 10.5.3.2 Detailed Carbonate & Evaporite Mineralogy..............................81 10.6 LENORE LAKE........................................................................................................84 10.7 QUILL LAKES..........................................................................................................84 10.7.1 Sedimentology & Stratigraphy...................................................................87 10.8. LITTLE MANITOU LAKE.....................................................................................88 10.8.1 Water Chemistry.........................................................................................88 10.8.2 Modern Sediments & Stratigraphy.............................................................90 11. NOTES