Abstract:Some felsic dykes have been discovered in recent years in the Qiuwangchong mining area, located in the eastern part of the EW-striking Baimashan-Ziyunshan metallogenic belt in central Hunan. Petrology and whole-rock geochemistry of these felsic dykes were studied in this paper. It is revealed that these dykes, lithologically, are mainly composed of porphyritic granite, tourmaline-bearing granite and graphic granite. In terms of geochemical characteristics of elements, these dykes in the Qiuwangchong deposit belong to the metaluminous to weakly peraluminous, calc-alkaline granite, and exhibit Si- and alkaline-enrichment signature. All dykes are rich in K, Rb, Th, U, Ce,Nd, Zr and Hf, but obviously depleted in Ba, Sr, P and Ti. In general, the total REE concentrations in these dykes are relatively low, and no obvious fractionation took place between LREE and HREE. All dykes are characterized by HREE-enrichment, with an extremely obvious negative Eu anomaly. Based on the discrimination diagrams of petrogenetic types and tectonic setting, in combination with previous studies for regional dykes, it is concluded that the dykes in this study belong to the highly-fractionated I-type granite, which was emplaced under the post-orogenetic extensional tectonic background. According to geological data in the study area and its adjacent areas, it can be concluded that these dykes are spatially associated with gold mineralization, and they are indicative of ore genesis and the further prospecting for gold mineralization in the study area.