METHODOLOGY FOR THE STUDY OF MELT INCLUSIONS IN CR-SPINEL, AND IMPLICATIONS FOR PARENTAL MELTS OF MORB FROM FAMOUS AREA

Melt inclusions trapped in Cr-spinel in mid-ocean ridge picrites (FAMO US area, Atlantic Ocean) were studied using a heating stage and analyz ed with both electron and ion microprobes. This new technique can prov ide information on the most primitive magma compositions, olivine-spin el-melt compositional relationships, crystallization temperature and g eochemical diversity of parental melts. The study of melt inclusions i n spinel can be applied to different high-Mg suites to show the effect s of shallow level fractionation, mixing and contamination that usuall y affect the composition of volcanic rocks and glasses.