- 责任者：Xie Lei (State Key Laboratory for Mineral Deposits Research ; School of Earth Sciences and Engineering ; Nanjing University ; Nanjing 210093 ; China) ; Wang Rucheng
- 刊名：Acta Petrologica Sinica
- 出版年：2013
- 卷期：29(12)
- 关键词：钨矿 ; tungsten ores ; 锡矿 ; tin ores ; 长英质成分 ; felsic composition ; 湖南 ; Hunan Province
- 页码：p.4261-4280
- 图表：9 illus., 4 tables, 98 refs.
- 分类号：1001
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
Felsic dyke is very common in the Nanling Range, as well as large scale of granitic plutons. In this study, six dykes in Qiguling, Xianghualing, Hehuaping, Qianlisha, Xintianling and Yaogangxian are selected as samples, which belong to different types （such as rhyolitic, fine-grained granitic and apltic） with various fractionated degree. Base on the whole rock analyses and chemical results of minerals, the features of petrology, mineralogy, chronology and geochemistry of these dykes are summarized and contrasted. Qiguling and Xianghualing dykes are two most highly fractionated rocks among six samples with very low Zr/Hf ratio in the whole rock and the zircons. They are enriched in volatile components （such as Li and F） and contain topaz and zinnwaldite. Nb, Ta, W and Sn are high in these two rocks, in the distinctive occurrence of oxide minerals, such as cassiterite, rutile and columbite. The other four dykes are barren. Only some secondary rutile with Nb and W enrichment occur in the cleavage of the chlorite, which developed by the alteration of the biotite. The dykes and their hosted or adjacent granites formed contemporaneously other than Qianlishan, however there is no confirmable relationship between them. They are sub-volcanic or volcanic analogue of granite, including the phenocryst and groundmass. Unique petrography, mineralogical assemblages and chemical results of minerals result from quenched and crystallized process, which recorded the complete magmatic-hydrothermal process. Combined these geological information, we indicate that the Xianghualing dyke is formed as a result of further fractionation of the Laiziling granite. While the origins between the Qiguling dyke and the hosted granite are distinct and the Qianlishan dyke and the hosted granite are also derived by the different source. No obvious petrogenetic and mineralized relationships have been found between the dykes and their hosted granite in Hehuaping, Xintianling and Yaogangxian. Therefore, no matter there is close relationship between the host granite and the dyke, the large-scale felsic dykes, especially high-evolved ones related to different kinds of mineralizations, are important indicators for the concealed host pluton and potential mineralization.