低δ18O岩浆岩的形成必然伴随着大气降水或者海水的参与，从低δ18O岩浆中结晶出来的锆石往往具有较大的变化范围。为了了解低δ18O锆石的水含量、水的存在形式、水进入锆石晶格的方式以及水对氧同位素的影响，本申请拟对华南北缘新元古代低δ18O花岗岩、火山岩、中国东部低δ18O花岗岩分别进行研究，在传统的岩石学和地球化学研究基础上，结合锆石拉曼光谱分析、离子探针锆石水含量和氧同位素分析、激光剥蚀锆石微量元素分析等微区分析手段，探明不同时代、不同成因、不同放射性损伤程度的低δ18O锆石的水含量及其氧同位素组成，查明其存在形式及与氧同位素的协变关系，理解水在低δ18O锆石结晶前、结晶过程中、结晶后所起到的作用，限定锆石在岩浆结晶以及结晶后热液蚀变过程中的微观行为和机制。

The meteoric water or sea water is inevitably involved in the origin of low δ18O igneous rocks. And the zircons crystallized from low δ18O igneous rocks usually have wide ranges which requires further study and proper interpretation. The aim of this proposal is to understand the contents of water, the species of water, the incorporation mechanism of water in zircon crystals and its potential influence on oxygen isotope compositions. The research targets includes the Neoproterozoic granitoids and volcanics in the north margin of South China, the Mesozoic granitic rocks in eastern China, both of which are characterized by low δ18O values. The zircon Raman spectroscopy, water and oxygen isotope analyses by SIMS, trace element analyses by LA-ICPMS will be carried out on the basis of petrological study, whole-rock major and trace element and Sr-Nd isotope analyses. The water concentrations and δ18O values will be determined for zircons of different age, different origin and different degrees of radiation damage. The incorporation mechanism of water and its correlation with oxygen isotope compositions will be explored. The results will be used to improve the understanding on the role of water before, during and after the crystallization of low δ18O zircons. The ultimate aim is to constrain the behavior and mechanism of zircon during the magma crystallization and hydrothermal alteration processes from a microscale perspective.