SCIENCE OBJECTIVES AND GOALS: THE MARS EXPLORATION ROVER SPIRIT ACQUIRED A RICH SET OF DATA THAT CONTINUES TO PROVIDE NEW KNOWLEDGE ABOUT PAST AND PRESENT ENVIRONMENTS AND GEOLOGIC PROCESSES ON MARS. A RECENT PAPER PRESENTS EVIDENCE THAT SOME OF THE PREVIOUSLY IDENTIFIED OUTCROPS OF OPALINE SILICA (AMORPHOUS SIO2*NH2O) ADJACENT TO THE HOME PLATE FEATURE MAY HAVE THIN CRUSTS OF HALITE (NACL). ENIGMATIC MINI-TES SPECTRAL CHARACTERISTICS OF THESE ROCKS CAN BE EXPLAINED BY THE PRESENCE OF A HALITE CRUST AS SHOWN BY COMPARISONS WITH HALITE ENCRUSTED OPALINE SILICA SINTER FROM A GEOTHERMAL FIELD AT THE EDGE OF THE ATACAMA DESERT IN CHILE. OUR OBJECTIVE IS TO TEST THIS SCENARIO WITH MORE SYSTEMATIC LABORATORY STUDIES IN ORDER TO FULLY INTERPRET NOT ONLY MINI-TES SPECTRA BUT ALSO THOSE FROM PANCAM AND GEOCHEMISTRY OBTAINED WITH APXS. OUR GOAL IS TO PRODUCE MORE ROBUST CONSTRAINTS ON THE NATURE OF THE HYDROTHERMAL SYSTEM THAT PRODUCED THE SILICA AND THE ENVIRONMENTAL CONDITIONS AT THE TIME OF FORMATION. HALITE ENCRUSTED SILICA ON EARTH IS KNOWN TO ARISE UNDER VERY RESTRICTED CONDITIONS. OUR INVESTIGATION OF A SET OF LITTLE STUDIED MINI-TES SPECTRA OF IGNEOUS ROCKS FOLLOWS ON TWO SUCCESSFUL PRIOR MDAP PROPOSALS AIMED AT MAXIMIZING THE SCIENTIFIC RETURN FROM THE MINI-TES INVESTIGATION IN GUSEV CRATER. PREVIOUSLY FUNDED PUBLISHED STUDIES INVESTIGATED THE SPECTRAL AND MINERALOGICAL DIVERSITY OF THE ADIRONDACK-CLASS OLIVINE BASALTS AND LINKS BETWEEN THE WISHSTONE- AND WATCHTOWER CLASSES. HERE WE PROPOSE TO CONTINUE OUR WORK BY INVESTIGATING THE MINERALOGY OF IGNEOUS ROCKS IN PROXIMITY TO COMANCHE CARBONATE OUTCROPS AND HOME PLATE SILICA. OUR GOAL IS TO MORE FULLY INVESTIGATE A SUITE OF MINI-TES SPECTRA OF IGNEOUS ROCKS THAT HAVE THE POTENTIAL TO REVEAL EVIDENCE OF AQUEOUS ALTERATION AND TO BETTER INFORM OUR UNDERSTANDING OF IGNEOUS PROCESSES ON MARS.