Testing Established Models of Hydrothermal Fluid Distribution Around Porphyry Deposits: The Application of Fluid Inclusion Research to Porphyry Deposit Exploration

.................................................................................................................................. iii LIST OF TABLES ........................................................................................................................ vii LIST OF FIGURES ..................................................................................................................... viii CHAPTER 1:INTRODUCTION .....................................................................................................1 CHAPTER 2: BACKGROUND ......................................................................................................4 Porphyry Deposits ........................................................................................................................4 The Kabba Prospect ..................................................................................................................12 CHAPTER 3: METHODS ............................................................................................................17 Sample Selection and Fieldwork: Hanging Wall .......................................................................17 Sample Selection and Fieldwork: Footwall ...............................................................................17 Doubly Polished Thick Section Sample Selection .....................................................................18 Conventional Petrographic Analysis .........................................................................................18 Scaning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS)/ Cathodaluminescence (SEM-CL) Analysis ................................................................................19 Microthermometry ......................................................................................................................20 Raman Analysis ..........................................................................................................................20 Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) ......................21 CHAPTER 4: VEINS AND ALTERATION ...............................................................................22 Host Rocks: Footwall .................................................................................................................22 Vein Assemblages: Footwall ......................................................................................................22 Veins: Footwall ..........................................................................................................................25 Host Rocks: Hanging Wall .........................................................................................................26 Vein Assemblages: Hanging Wall ..............................................................................................27 Veins: Hanging Wall ..................................................................................................................30 A Veins ...............................................................................................................................30 B Veins ..............................................................................................................................32 D Veins ...............................................................................................................................33 Alteration in Footwall and Hanging Wall Rocks .......................................................................34 Potassic Alteration .............................................................................................................34 vi Green Mica Alteration ......................................................................................................35 Coarse Mica Alteration......................................................................................................36 Vein and Alteration Interpretation: Footwall ............................................................................37 Vein and Alteration Interpretation: Hanging Wall ....................................................................39 CHAPTER 5: FLUID INCLUSION PETROGRAPHY AND ANALYSIS ................................42 Fluid Inclusion Assemblages (FIAs) ..........................................................................................42 Fluid Inclusion Group Assignment and Notation ......................................................................43 Fluid Inclusion Group: Footwall ...............................................................................................44 Fluid Inclusion Group: Hanging Wall .......................................................................................46 Fluid Inclusion Group Distribution ...........................................................................................50 Microthermometric Evaluation of CO2 Content ........................................................................51 Raman Analysis ..........................................................................................................................52 Microthermometry: Application .................................................................................................55 Microthermometry: Footwall .....................................................................................................57 Microthermometry: Hanging Wall .............................................................................................58 CHAPTER 6: LA-ICP-MS ...........................................................................................................65 LA-ICP-MS Results: Footwall ...................................................................................................66 LA-ICP-MS Results: Hanging Wall ...........................................................................................70 Patterns and Interpretation of LA-ICP-MS Data ......................................................................84 CHAPTER 7: DISCUSSION AND INTERPRETATION ...........................................................88 CHAPTER 8: CONCLUSION ...................................................................................................101 APPENDICES ............................................................................................................................137 APPENDIX A HANGING WALL SAMPLES AND ANALYSIS .........................................137 APPENDIX B FOOTWALL SAMPLES AND ANALYSIS .................................................139 APPENDIX C HANGING WALL HAND SAMPLE AND DESCRIPTIONS .....................142 APPENDIX D FOOTWALL HAND SAMPLE AND DESCRIPTIONS ..............................148 APPENDIX E MICROTHERMOMETRIC OBSERVATIONS AND DATA ......................158 APPENDIX F UNPROCESSED LA-ICP-MS DATA ............................................................177 APPENDIX G SUMMARY OF LA-ICP-MS DATA ............................................................194 REFERENCES ...........................................................................................................................198 CURRICULUM VITAE .............................................................................................................202