Potential Applications of Fe and Mg Isotopes in Genesis of Chromite Deposits in Ophiolites
Su Benxun
Xiao Yan
Chen Chen
Bai Yang
Liu Xia
Liang Zi
Peng Qingshan
Abstract：Genesis of chromittie deposit in ophiolites has been debated for a long time.It is commonly related to host ophiolite, chromite occurrence,simple mineral assemblage and simple mineral chemistry,and unusual and complicated mineral inclu-sions.To constrain the genesis of chromite,a study on Fe and Mg isotopes of mantle peridotite and chromitite from Purang and Luobusa ophiolites in Tibet and K1z1ldaˇg and Kop ophiolites in Turkey is conducted.The results reveal that(1)mantle perido-tite of ophiolites has uniform Fe and Mg isotope compositions,falling in the same range of worldwide peridotite;(2)chromite and olivine in chromitite show large Fe and Mg isotope fractionations with overall lower δ56Fe and higher δ26Mg in chromite than olivine;(3)Fe and Mg isotope fractionations between chromite and olivine are mainly controlled by fractional crystalliza-tion and subsolidus Fe and Mg exchanges in two opposite processes.Therefore,Fe and Mg isotopes have great potentials to trace origin and nature of parental magmas of chromitite and crystallization and precipitation of chromite.
Keywords：ophiolitechromiteFe isotopeMg isotopepetrologymineralogy
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 1011-1024 )