本课题瞄准国际上天然金刚石研究方面的难点、前沿，尝试利用纳米离子探针等先进测试技术，分析扬子克拉通西部砂矿金刚石多晶聚合体中的金刚石晶粒、共生矿物及包裹体的微结构、微成分，厘定它们的精细信息差异及形成的关键性制约因素和条件，包括晶粒形成所需的温度、压力、氧逸度条件及结晶速度，晶粒联结所需的驱动力及媒介，晶粒微结构、微成分的标型特征,标型矿物（组合）等，构建该区天然金刚石多晶聚合体的形成机制，探究扬子克拉通西部不同类型砂矿金刚石多晶聚合体形成的地质地球化学环境以及对深部过程的响应。本研究将突破国际上较长时期以来将金刚石多晶聚合体看成一个"均匀"体系进行地球化学研究的局限性，为人们深入探索金刚石多晶聚合体的成因、来源及意义等奠定坚实的基础。同时，也将加深乃至更新人们对扬子克拉通西部深部过程的认识，为该区砂矿金刚石的成因、来源研究及找矿探索等提供新的思路。

This project focus on the natural diamond polycrystalline aggregate which has been studied as an international difficult and frontier scientific subject. The modern analysis techniques (NanoSIMS, etc.) will be used to study the micro-texture and micro-ingredients of diamond grains and coexisting minerals as well as the inclusions within them in the placer diamond polycrystalline aggregates from the western part of the Yangtze Craton. The fine differences among them will be distinguished, and used to determine the key factors and conditions of their formation, such as the P-T-f O2, crystallization rate and driving force as well as the markers of micro-texture and micro-ingredients. The relationship between the micro-textures and micro-ingredients and the formation mechanism model of the diamond polycrystalline aggregates and the geological environment evolution of deep earth will be discussed in detail. This study will certainly deepen the understanding of the geological and geochemical environment for the formation of the diamond polycrystalline aggregates as well as the evolution of the deep earth in the western part of the Yangtze Craton. It may also be expected to provide new significant ideas for the study of the formation and origin of diamonds and the primary diamond deposit prospecting in the western part of the Yangtze Craton.