Nb- Ta minerals in metasomatic skarn from Yuge Is.

Abstract

The metasomatic skarn that aggregate of purple fluorite is considered with radiogenic halo by Th minerals occur rarely is found Yuge Island in Ehime Prefecture(Ogoshi & Minakawa, 2009). Oxycalciobetafite[Ca₂Ti₂O₆O] and kobeite-(Y)[Y(Zr,Nb)(Ti,Fe³⁺)₂O₇] associated ilmenite and titanite closely are found in this skarn. oxycalciobetafite from Yuge island form continuous solid solution with Y+REE component and vacancy component, and Kobeite-(Y) from Yuge island form continuous solid solution with zirconolite. Occurrence of betafite group minerals do not report in Japan, and kobeite-(Y) associated with zirconolite and occurred from skarn report frist.