Investigations of garnets from polymetamorphic rocks of the Lapland Granulite Belt of the Kandalaksha Region

Abstract

Introduction: The Lapland Granulite Belt is placed on the Kandalaksha region (Kola Peninsula, Russia). The rocks of this Belt are composed mainly of amphibolites and granulites. Materials and methods: The research were focused on the garnets from the amphibolite and granulite rocks of Lapland Granulite Belt. The petrological methods like polarizing microscopy (PM), SEM-EDS, XRD for powdered samples and single crystal diffraction were used together with IR and Mossbauer spectroscopy and REE analysis by ion–microprobe. Results: It was found that the garnets from studied amphibolite and granulite rocks could be classified to pyralspite group without hydrogarnets components, so they were formed in high metamorphic facies. Conclusions: The joint geological observations and results of the performed experiments suggest that the garnets were subject of a blastesy, i.e. there were formed in long lasting metamorphic processes of low dynamics, except of those garnets from tectonic zones, found in the vicinity of mineral veins.