Mars-Relevant Phosphate Minerals and Implications for Martian Habitability

......................................................................................................................iii ACKNOWLEDGEMENTS ................................................................................................ v LIST OF TABLES .............................................................................................................xi LIST OF FIGURES ......................................................................................................... xiii CHAPTER ONE INTRODUCTION AND OVERVIEW ................................................ 1 CHAPTER TWO SYNTHESIS AND CHARACTERIZATION OF THE MARSRELEVANT PHOSPHATE MINERALS FEAND MGWHITLOCKITE AND MERRILLITE AND A POSSIBLE MECHANISM THAT MAINTAINS CHARGE BALANCE DURING WHITLOCKITE TO MERRILLITE TRANSFORMATION ............... 6 Abstract ............................................................................................................................... 6 Introduction ......................................................................................................................... 7 Background ......................................................................................................................... 9 Methods............................................................................................................................. 13 Whitlockite synthesis ................................................................................ 13 Merrillite synthesis.................................................................................... 14 Analytical Methods ................................................................................... 16 Results and Discussion ..................................................................................................... 18 Optimization of Whitlockite Synthesis ..................................................... 18 Merrillite Synthesis ................................................................................... 22 Crystallography ......................................................................................... 30 Implications for Martian Studies ...................................................................................... 33 Acknowledgements ........................................................................................................... 34 Tables ................................................................................................................................ 36 Figures............................................................................................................................... 40 CHAPTER THREE READILY AVAILABLE PHOSPHATE FROM MINERALS IN EARLY AQUEOUS ENVIRONMENTS ON MARS. ........................ 44 Abstract ............................................................................................................................. 44 Introduction ....................................................................................................................... 44 Methods............................................................................................................................. 52 Acknowledgments............................................................................................................. 53 Tables ................................................................................................................................ 54