Multistages of original sapphire formation related to basaltic magmatism in the Bo Phloi basaltic gem field, Kanchanaburi, Western Thailand: Evidence from trace elements and ages of zircons

Trace element geochemistry of zircons in the Bo Phloi basaltic gem deposit, Kanchanaburi, Western Thailand indicates that majority of the sapphires and associated minerals appear to have crystallized in an environment related to highly alkaline felsic melt with subordinate collaboration of contact metamorphism at the lower crust. The U-Pb dating of a zircon inclusion in sapphire and zircons in two sapphire-bearing gravels yielded the average...