WHETHER MARS' MOST ANCIENT TIME PERIOD WAS PREDOMINANTLY "WARM AND WET " WITH PERENNIALLY FLOWING SURFACE WATER OR "COLD AND ICY " WHEREIN WIDESPREAD GLACIATION WAS PUNCTUATED ONLY PERIODICALLY BY WARMER CONDITIONS IS A CRITICAL ISSUE IN MODERN MARTIAN SCIENCE. HOWEVER OBSERVATIONS OF WATER-RELATED SURFACE FEATURES AND MODELS OF THE ANCIENT CLIMATE HAVE NOT YET CONSTRUCTED A COMPREHENSIVE EXPLANATION. THIS PROJECT TAKES A DIFFERENT APPROACH BY ADDRESSING THE QUESTION: TO WHAT EXTENT HAVE GLACIATION AND COLD-CLIMATE WEATHERING CHEMICALLY ALTERED THE SURFACE OF MARS? IF GLACIAL OR COLD CLIMATE PROCESSES PLAYED A SIGNIFICANT ROLE IN MARS' EARLY CLIMATE WE MIGHT EXPECT TO SEE SUBSTANTIATING MINERALOGICAL EVIDENCE PRESERVED IN THE MARTIAN GEOLOGIC RECORD. COLD AND GLACIAL CLIMATES APPEAR TO PREDOMINANTLY PRODUCE AMORPHOUS SILICATE MINERALS WHICH HAVE BEEN IDENTIFIED WIDELY ON MARS BUT COMPREHENSIVE ANALYSIS OF THE CONTRIBUTION OF SPECIFICALLY COLD AND ICY ENVIRONMENTS TO THE FORMATION OF AMORPHOUS SILICATE MATERIALS ON MARS IS LACKING IN THE LITERATURE. IN THIS STUDY I WILL TEST THE HYPOTHESIS THAT COLD CLIMATES COULD HAVE FORMED HYDRATED AMORPHOUS SILICATES ON MARS. FREEZE-THAW CYCLING FORCES DISSOLVED SOLUTES OUT OF SOLUTION AS PRECIPITATES AND FIELDWORK RESULTS AND THE LITERATURE INDICATE THIS PROCESS MAY DEPOSIT AMORPHOUS SILICA OVER TIME BUT THIS PROCESS NOT BEEN CHARACTERIZED IN A CONTROLLED SETTING ON MAFIC ROCKS. MY FIRST OBJECTIVE WILL BE TO CONDUCT A RANGE OF FREEZE-THAW WEATHERING EXPERIMENTS ON MAFIC ROCKS AND SEDIMENT TO CHARACTERIZE THE COMPOSITION AND RATE OF FORMATION OF ALTERATION PRODUCTS IN A KNOWN SYSTEM. I WILL USE A COMBINATION OF VISIBLE/NEAR-INFRARED AND MID-INFRARED SPECTROSCOPY X-RAY DIFFRACTION ELECTRON MICROSCOPY AND WATER CHEMISTRY TO IDENTIFY MINERALS PRECIPITATED DURING THE EXPERIMENTS CHARACTERIZE THE ALTERATION PROCESS AND ESTIMATE RATES OF FORMATION IN ORDER TO DRAW INFERENCES ABOUT THE IMPORTANCE OF FREEZE-THAW TO CHEMICAL WEATHERING IN COLD ENVIRONMENTS ON EARTH AND MARS. MY SECOND OBJECTIVE WILL BE TO SEARCH FOR PRODUCTS FORMED IN THE BASALT WEATHERING EXPERIMENTS AS WELL AS PRODUCTS PREVIOUSLY FOUND AT A MARS GLACIAL ANALOG SITE IN ASSOCIATION WITH GLACIAL GEOMORPHOLOGIES ON MARS USING DATA FROM THE COMPACT RECONAISSANCE IMAGING SPECTROMETER FOR MARS (CRISM). SEARCHING FOR THE PRESENCE OF SIGNIFICANT COLD-CLIMATE ALTERATION PRODUCTS IN NOACHIAN-AGE TERRAINS WOULD HELP TEST THE HYPOTHESIS THAT THE NOACHIAN WAS PREDOMINANTLY COLD AND WET; THUS THIS PROJECT LAYS THE GROUNDWORK FOR SUCH A STUDY BY TESTING WHETHER MINERALOGICAL INDICATIONS OF COLD-CLIMATE ALTERATION ARE DETECTABLE FROM ORBIT. I WILL FOCUS THIS SEARCH ON GLACIER-LIKE FORMS (GLFS) WHERE GEOMORPHIC INDICATIONS OF WET-BASED GLACIATION AND/OR MELT ARE EVIDENT AND PROVIDE CONTEXTUAL BASIS FOR INTERPRETATIONS. THIS WORK PROVIDES CONSTRAINTS ON MORPHOLOGY-BASED INTERPRETATIONS OF WET GLACIATION AIDS IN UNDERSTANDING THE VARIABILITY OF "COLD AND WET" VERSUS "COLD AND DRY" CLIMATE THROUGHOUT MARS' HISTORY AND LAYS THE GROUNDWORK FOR MINERALOGYBASED INTERPRETATIONS OF COLD CLIMATES ON MARS. THIS PROJECT WILL INFORM OUR UNDERSTANDING OF THE FUNDAMENTAL GEOCHEMICAL PROCESSES MODIFYING THE MARTIAN SURFACE WHICH IS DIRECTLY ALIGNED WITH THE NASA SCIENCE MISSION DIRECTORATE (SMD) PLANETARY SCIENCE GOAL TO "ADVANCE THE UNDERSTANDING OF HOW THE CHEMICAL AND PHYSICAL PROCESSES IN THE SOLAR SYSTEM OPERATE INTERACT AND EVOLVE."