Origin of the deep metamorphic complexes of the Early Proterozoic folded framing, the eastern part of the Aldan shield

It is shown that the base of the geologic section of the deep-seated Early Proterozoic Dzhugdzhur and Sunnagin complexes is made up of granulite-facies crystal schists and plagiogneisses, which are distinguished as the metabasite-enderbite association. As indicated by the major- and trace-element distribution, the predominant protolith of this rock association includes volcanics of the calc-alkaline and komatiite-tholeiitic series. The accepted model of the formation of the primary volcanics of the metabasite-enderbite association includes two stages. The first stage provides formation of melts of komatiite-tholeiitic series via decompressional melting of the material of an ascending mantle plume. The second stage involves the formation of calcalkaline volcanics owing to the partial melting of the initial metabasite crust by the heat of the ascending mantle plume. The igneous protoliths of the metabasite-enderbite association were formed in the Early Proterozoic.