Li-bearing micas as a fractionation indicator of tin granites: The Sadisdorf-Schellerhau granite suite, Eastern Erzgebirge

摘要

The trend of granite fractionation during the multiphase evolution of the Sadisdorf-Schellerhau granite system has been studied from the viewpoint of composition of Li-bearing micas. The composition of these micas displays distinct differences with progressive fractionation from low-evolved biotite granites (Gl) containing siderophyllite and protolithionite to the highly-evolved topaz-albite granites (G2, G3, G4), in which zinnwaldite, lepidolite and Li-phengite formed. This study contributes to a better understanding of the development and behavior of fractionated tin-bearing granite melts and links mica chemistry with geological relationships.