稀有金属锂矿是我国紧需的战略性矿产资源。滇西地区是我国重要的稀有金属成矿远景区, 但目前区内已知的稀有金属资源主要为Be-Nb-Ta-Sn矿, 鲜有锂矿的报道。本研究首次在滇西高黎贡山培里地区发现了锂辉石伟晶岩型锂矿, 为云南省新增一处有潜力的锂辉石型伟晶岩锂矿床, 对区域稀有金属锂矿床的找矿工作具有重要意义。6个样品的全岩主微量元素分析显示培里地区伟晶岩主要发育有Li、Be、Rb、Cs、Nb、Ta矿化。LA-ICP-MS铌钽矿U-Pb年代学结果显示培里地区锂矿伟晶岩形成于18.4±0.3Ma, 这一结果与共生的锡石U-Pb年代学(17.5±1.2Ma)结果一致, 表明其为新生代成岩成矿作用产物。这一成矿年代与高黎贡山地区变质年代以及淡色花岗岩成岩年代一致, 暗示培里伟晶岩可能为变质重熔产物, 也可能是淡色花岗岩进一步结晶分异的产物。在大区域尺度上, 该成矿事件与藏南稀有金属成矿时代一致, 结合区域显著的地球化学背景异常, 我们认为滇西地区可能是喜马拉雅稀有金属成矿带的南延部分, 具有良好的稀有金属锂矿找矿前景。

The initial enrichment of rare earth elements (REE) in granites plays an important role for the generation of ion-adsorption type REE deposits. It has been summarized that the mineralization-related granitoids are mostly peraluminous, but the enrichment mechanism of REE in this peraluminous granite is currently not well understood. In this study, we conducted geochronology, petrological, and geochemical investigations on the biotite granite and muscovite granite from the Shangyou complex in Ganzhou, Jiangxi Province. Zircon U-Pb dating indicates that both the biotite granite and muscovite granite generated in the Early Silurian (ca. 433–434 Ma). The high aluminum saturation index and occurrence of muscovite and old zircon cores indicate that they belong to the S-type granite and are derived from the melting of metagreywacke. The relatively higher FeO^T contents, Mg# values, and zirconium saturation temperatures (760–873 °C) for the biotite granite resulted from hydrous melting with the involvement of mantle material. In contrast, the muscovite granite with low FeO^T contents, Mg# values, Nb/Ta ratios, and zirconium saturation temperatures (748–761 °C) indicates a purely crust-derived melt formed by muscovite dehydration melting. There is a positive correlation of REE contents with the formation temperature and Th contents in both the Shangyou granites and the data collected from global peraluminous granites. This indicates that temperature plays a key role in the REE enrichment in peraluminous granites, as the high-temperature condition could promote the melting of REE-rich and Th-rich accessory minerals of allanite and REE-phosphate and result in the increases in both REE contents and Th contents in the melts. Given the fact that the parent granites for ion-adsorbing REE deposits are mostly peraluminous and generated in the extensional setting in South China, we concluded that peraluminous granite formed under high-temperature extensional tectonic settings favors initial REE enrichment, which further contributes to the formation of ion-adsorbing REE deposits in South China.