Potassic alkali basaltoids and geochemical specialization of associated rare-metal granites

geochemical analysis has shown that K-basaltoids-monzonitoids and rare-meta l granites were initially enriched in incompatible volatile and trace grani tophile elements. This enrichment was nonuniform in different provinces and magmatic systems. It is shown that the rare-metal content and ore-bearing capacity of granites are governed by a potassium concentration and, corresp ondingly, a rare-metal content in subalkalic basaltoids associated with gra nites. This evidences endogenic nature of the geochemical and metallogenic specialization of ore-bearing granite intrusions in rare-metal provinces. T he K-richest basaltoids formed earlier than large ore-bearing intrusions of late-orogenic rare-metal granites. Moderate-K basaltoids are related to th e less productive rare-metal granite magmatism of the postorogenic stage. The enrichment of basaltoids in volatiles and increase in their rare-metal contents during the evolution of K-basaltoid-monzonitoid and granitoid intr usive systems suggest that all these elements were transported with fluids to basaltoid magma chambers and crustal granitoid melts formed in deep-faul t zones.