RARE-EARTH AND OTHER TRACE ELEMENTS IN ROCKS FOR BEARING MAGMATIC COMPLEXES

Abstract

W-bearing magmatic complexes of the southern Tien Shan are distinguished from one another by the depths of magma sources and their composition, which are made up of metasomatically enriched mantle, primitive or depleted mantle, or metabasic or metapelitic granitized crustal rocks. The subsequent evolution of melts was controlled by the fractionation of accessory and mafic rock-forming minerals in some of the rocks and by feldspar fractionation in others. The concentrator minerals of tungsten ceased to fractionate late during the magmatic evolution, giving rise to the enrichment of the residual melts in this metal.