IRON-RICH OLIVINE IS ONE OF THE MOST ABUNDANT PHASES IN THE MATRICES OF ORDINARY AND CARBONACEOUS CHONDRITES. ALTHOUGH THERE ARE A LOT OF STUDIES OF THE OCCURRENCE OF FEO-RICH OLIVINE ITS ORIGIN IS POORLY UNDERSTOOD. THIS PROPOSAL AIMS TO UNDERSTAND THE HYDROTHERMAL ALTERATION AND FLUID-ASSISTED METAMORPHIC GROWTH OF FEO-RICH OLIVINE ON THE PARENT BODIES OF ORDINARY AND CARBONACEOUS CHONDRITES THROUGH DETAILED ANALYSIS OF THE MINERALOGY TEXTURE CHEMICAL COMPOSITION AND CRYSTALLOGRAPHY OF OLIVINES FORMED DURING EXPERIMENTS. THE EXPERIMENTS WILL BE CONDUCTED AT OPTIMAL CONDITIONS OF ASTEROIDAL PARENT BODIES. WE WILL SYNTHESIZE FEO-RICH OLIVINES AND CONSTRAIN THE CONDITIONS OF THEIR FORMATION AT DIFFERENT TEMPERATURES WATER-TO-ROCK (W/R) MASS RATIOS DURATIONS AND BULK ROCK COMPOSITIONS. THE PROPOSED RESEARCH WILL HAVE IMPORTANT IMPLICATIONS FOR UNDERSTANDING THE CHEMICAL REACTIONS AND THE ROLE OF FLUIDS IN THE FLUID-ASSISTED METAMORPHISM THAT AFFECTED THE MATRICES OF ORDINARY AND CARBONACEOUS CHONDRITES. ADDITIONALLY WE WILL INVESTIGATE THE EFFECT OF DEHYDRATION TREATMENTS OF THE HYDROTHERMAL ALTERATION PRODUCTS TO UNDERSTAND THE KINETICS OF RECRYSTALLIZATION OF SECONDARY PHASES.