Genesis of Charoite Rocks in the Murun Massif, Aldan Shield, Russia

Abstract

Data on mineral-hosted inclusions indicate that the charoite rocks crystallized in a heterogeneous medium of carbonate–silicate and carbonate melts, gaseous and H₂O–salt fluids. Our results indicate that the early rock-forming minerals of the charoite rocks started to crystallize at high temperatures (>800°C), and crystallization may have terminated at lower temperatures (600–450°С). Data on the melt and fluid inclusions confirm the conclusion that the charoite rocks are of magmatic origin. The facts that these rocks are typically found as vein- and lens-shaped bodies, the composition of these rocks does not correlate with the composition of the host rocks, and the occurrence of chilled fine-grained domains of the charoite rocks also suggest that these rocks crystallized from magmatic melt.