F-Cl compositions of apatite in post-metamorphic dykes intruded on Rundvågshtta, Lützow-Holm Complex, East Antarctica, and compositional relation among their composed minerals.

Abstract

On Rundvågshetta in the LHC, intermediate to mafic dyke rocks were found in some places.  Relatively mafic rocks contain apatite with much fluorine; on the other hand, less mafic rocks have apatite with F-rich core and Cl-rich rim.  This suggests compositional progression from fluorine to chlorine in the less mafic condition during apatite crystallization.