喷发到地球表面的幔源岩浆岩的成分代表经历一系列复杂过程的综合产物：从地幔部分熔融形成熔体开始，到熔体从源区提取出来，最后上升到浅部发生岩浆分异、熔体-岩石相互作用、岩浆混合等。与喷发熔岩相比，矿物及其捕获的熔体包裹体通常显示更大的成分变化范围，原则上能保存岩浆广泛混合之前和岩浆演化过程的信息。本项目拟对南海扩张期后火山角砾中的单矿物，基质玻璃，熔体包裹体的化学成分和同位素组成进行系统研究。揭示南海海盆停止扩张后形成的岩浆的化学成分、性质随时间的变化规律，评估浅部岩浆过程对岩浆成分的影响，进一步推断深部地幔源区组成，为地幔不均一性的成因提供制约。

The chemical composition of mantle-derived magmatic rocks erupted at the Earth’s surface is the end product of a complex series of processes, beginning with partial melting and melt extraction from a mantle source and ending with fractional crystallization, melt-rock interaction and magma mixing at lower pressures. Melt inclusions and their host minerals often span a much greater compositional range than associated erupted lavas, which in principle can preserve the compositional characteristics of early melts before they have mixed in magma chambers, and may provide a history of magmatic processes that have occurred. In this study, chemical and isotopic analyses will be made for melt inclusions, minerals and host glasses in volcaniclastic breccia from the South China Sea. The aim of this study is to reveal temporal variations in the composition of magmas formed after cessation of spreading, to investigate the role of magmatic processes on composition of magmas, to further infer the nature and origin of mantle source components, and to provide constraint on the origin of mantle heterogeneity.