METAVOLCANIC ROCKS OF THE DJAGDAGLE FORMATION OF THE BUREYA CONTINENTAL MASSIF (CENTRAL ASIAN OROGENIC BELT): RESULTS OF GEOCHEMICAL AND SM-ND ISOTOPIC-GEOCHEMICAL STUDIES

The paper presents the results of geochemical and Sm-Nd isotopic-geochemical studies of metavolcanic rocks of the Djagdagle formation of the northwestern part of the Bureya continental massif. As a result of reconstruction of the primary composition of the metavolcanic rocks, the correspondence of their protoliths to the pantelleritic, comenditic rhyolites is shown. Nd-features of metavolcanic rocks of the Djagdagle formation indicate the melting of rocks of continental crust with Paleoproterozoic model ages during the formation of their initial melts. Geochemical features, close spatial position with Mongol-Okhotsk orogenic belt allow us to link the formation of initial melts of metavolcanic rocks of the Djagdagle formation with within-plate magmatism in the rear zone of subduction of the Mongol-Okhotsk Ocean beneath the northern (in modern coordinates) margin of the Bureya continental massif.