Geochemical types of cretaceous granitic rocks of Northeastern Russia

New data on the distribution of trace elements in the rocks of volcano-plutonic associations from the Cretaceous active continental margin of northeastern Russia were obtained. The volcanic and plutonic facies of the Okhotsk-Chukotka Volcanic Belt (OCVB) are shown to a be geochemically identical, Both facies form parts of the same differentiation series, in which the rocks with the same silica contents have similar trace-element compositions. The abundances of volatile components (F and B) are critical for the distribution of trace elements in granitic rocks, The leucogranites of Omsukchan district that are enriched in F and B bear a rare metal mineralization. The Rb versus (Nb + Y) plot was used to geochemically discriminate Cretaceous granitic rocks from northeastern Russia. Subduction-related and intraplate granites were distinguished. The former display an extremely low Nb content (< 10 ppm), Using geochemical fingerprints, the subduction-related granitic rocks were subdivided into an island-are group (Anadyr' area) and an active continental margin group (OCVB). The comparison of subduction-related granitic rocks from northeastern Russia with their collisional counterparts (the Main Batholithic Belt of eastern Yakutia) has shown that the subduction-related granites are slightly enriched in Mg and Cr and depleted in K and Rb. This is because their mineral assemblages originated ata higher temperature.