The first find of solid solutions thorite and xenotime in metapelite granulites of the Kursk-Besedino block (Voronezh crystalline massif)

Abstract

two unique grains of thorite-xenotime solid solutions solutions were found in metapelites of the Kursk-Besedino block (Voronezh crystalline massif). They are small (20-30 microns) roundish discharge localized in the feldspar matrix. Grain No. 1 is a natural standard for the complete miscibility of thorite and xenotime. Grain No. 2 is enriched with a thorite mineral. Water fixed in the analyzed grains expands the polar mixtures of multicomponent mineral systems. The source of minerals for thorite-xenotime solid solutions are hydrotherm penetrating through cracks and thin channels in the rock. The precipitation of galena in the structure of the studied solid solutions is an obstacle to determining the age of geological processes by the CHIME method.