Relationship Between Micas And Tin Mineralization

In previous studies, mica was known as a main carrier of tin. And it was also considered as an enriching mineral of tin, which means mica could reserve higher content of tin than the average content in whole-rock. Micas have complex structures. It is reported that tin may occur in crystal lattice or interlayers of mica. Kamusite tin deposit is a key part of the tin deposits belt of northern Xinjiang. In view of its spatial position related to granites, the deposit is an ideal research object to discuss the relationship between micas and tin mineralization.In this paper, serial samples of granites and greisens are applied to the experiments, in Kamusite tin deposit. According to the experiments, the contents of Sn are below detectable limit(0.1 wt.%), both in X-ray powder diffraction(interlayers of mica) and EMPA(crystal lattice of mica). Furthermore, integrated methods of whole-rock major and trace elements analysis and petrological/mineralogical observation are taken into account. It can be concluded that mica is not the main carrier mineral or enriching mineral of tin.In Kamusite tin deposit, tin mainly occurs in the intersections between micas and quartz, in disseminated colloid forms(wood tin). It can be speculated that differentiation of magma caused Sn concentrating in residual melts in early stage. In late stage, retrograde boiling ore-bearing hydrothermal solution caused dehydration. And wood tin was the crystallized product from rapid cooling hydrous tin.