MELT INCLUSIONS IN CLINOPYROXENE PHENOCRYSTS FROM MAFIC DIKES IN THE EASTERN NORTH CHINA CRATON: CONSTRAINTS ON MELT EVOLUTION

摘要

The estimated parental melt is basic with SiO_2rncontent 49.6 wt % and Mg# 80.0 and showsrnrelatively low total alkali concentrations (1.35 wt %rnNa_2O+K_2O) and high CaO content (15.2 wt %).rnLow-MgO and high-MgO SMIs were derivedrnfrom the same parental melt and were thernproduction of parental melt experiencing variousrndegrees of crystallization. Clinopyroxene and arnsmall amount of olivine were the fractionatingrnphases during the evolution from parental melt tornlow MgO melt. While the low MgO meltrnexperienced significant fractional crystallization ofrnolivine and clinopyroxene.