Bureya−Jiamusi−Khanka superterrane linked to the Kuunga-Pinjarra interior orogen of East Gondwana and its drift toward Northeast Asia

Abstract

There is general agreement that a series of East Asian blocks has always lain outboard of both India and Australia along the North Indo−Australie peripheral orogen. However, whether the East Asian blocks were involved in the interior orogens of East Gondwana remains equivocal. The geochronology and geochemistry of Neoproterozoic−Late Triassic rocks in the Russian Far East, together with existing paleontological and detrital zircon data, offer an opportunity to determine the tectonic origin and drift history of the Bureya−Jiamusi−Khanka superterrane. Biotite and amphibole 40Ar/39Ar dating results define a distinctive episode of Late Pan-African (ca. 550 Ma) metamorphism and a local Late Triassic (ca. 219−200 Ma) episode of deformation for the Bureya−Jiamusi−Khanka superterrane. Zircon U−Pb ages and whole-rock geochemical data indicate that the Early Ordovician (483 ± 3 Ma) highly fractionated I-type monzogranites were emplaced in a post-collisional setting linked to the collapse of a Late Pan-African orogen, while the Late Triassic (ca. 234−223 Ma) A-type quartz syenites and I-type granite aplite dikes were formed in a slab-pull−induced passive continental margin of the subducting Mudanjiang oceanic plate. These crucial archives, complemented by data from the literature, reveal that the Bureya−Jiamusi−Khanka superterrane made up the northernmost Kuunga-Pinjarra interior orogen during the final assembly of East Gondwana. As a result of Devonian rifting after Early Ordovician orogen collapse, the Bureya−Jiamusi−Khanka superterrane escaped from the Kuunga-Pinjarra interior orogen and subsequently migrated to Northeast Asia by the Late Triassic to Jurassic due to the subduction and closure of the Paleo-Tethys and Paleo-Pacific oceans.