A Tentative Discussion on Geochemistry and Genesis of Indium in Dachang Tin Ore District, Guangxi
This paper deals emphatically with the Changpo-Tongkeng deposit, Lame deposit and Gaofeng deposit, and analyzes In, Cu, Cd, Fe and Zn concentrations in their host rocks, ores, sulfides and oxides as well as in granite of the ore district. Based on EMPA data of sulfides and oxides, sulfur isotope data of sulfides, carbon and oxygen isotope data of host rocks and carbonate, the authors have found that the magma source is rich in indium in the Dachang ore district, whereas abnormal indium concentration exists in the host rocks. Most indium is hosted in sphalerite, and is closely associated with massive and layered ores. Indium was selectively concentrated and distributed in different mineral assemblages and ores during indium mineralization. It is held that the indium-rich magma source was a melt, which was subsequently emplaced and intruded into the upper crust.