岩浆岩的V同位素分馏:矿物结晶和氧逸度控制OA

Vanadium(V)is a redox-sensitive element,and its valence is controlled by the environmental redox conditions.In recent years,the advancement in MC-ICP-MS analytical techniques has enabled the precise identification of subtle V isotope fractionation in igneous systems.As a result,V isotopes have shown great potential in the study of high-temperature geological processes.Understanding the mechanism of V isotope fractionation during igneous evolution is fundamental to their application in high-temperature geochemical research.This paper reviews the research findings on V isotopes in igneous rocks and points out that mineral crystallization and oxygen fugacity are the main factors controlling V isotope fractionation.Studies have shown that the separation crystallization of silicate minerals can alter V isotope composition of the melt.Moreover,Fe-Ti oxides are key factors controlling V isotope fractionation,and their separation crystallization can lead to an increase in the δ51V value of the residual melt.Additionally,while previous studies suggested that the V isotopes of primitive basalts are not sensitive to changes in oxygen fugacity,recent views indicate that there is recognizable V isotope fractionation at lower degrees of partial melting and higher oxygen fugacity.Based on this,this paper summarizes the applications of V isotopes as follows:in tracing crustal evolution,V isotopes have allowed to establish a close link between felsic continental crust and plate tectonics;in constraining the formation of layered intrusions,V isotopes reveal an evolutionary path from primitive magmas to highly differentiated products;and in tracing mantle-derived magma sources,V isotopes suggest that partial melting and fractional crystallization jointly dominate the transformation of carbonate melts into alkaline basalts.These studies fully demonstrate the great potential of V isotopes in the study of high-temperature geological processes.