摘要
The neutral and basic volcanic recently discovered in Devonian stratum of Dachang tin deposit of Guangxi mainly comprise the basalt and andesite series, belong to calcium alkaline-alkaline series, and formed in the continental rift environment. The volcanic has the characteristics of rich light rare earths, high ratio of light to heavy rare earths, moderate losses of Eu and Ce, and high fractionation of heavy rare-earth element. According to the Q-cluster analysis of rare-earth element of the volcanic sample, the relationship between the ore and the layered volcanic is closed, demonstrating the inheritance and consistency to the layered volcanic. The deposit formed by means of volcano-hydrothermal exhalative sedimentation-late stage superposed and deformation.